CN114472896A - Method for strengthening hardness of brazing tool blank - Google Patents
Method for strengthening hardness of brazing tool blank Download PDFInfo
- Publication number
- CN114472896A CN114472896A CN202210064669.1A CN202210064669A CN114472896A CN 114472896 A CN114472896 A CN 114472896A CN 202210064669 A CN202210064669 A CN 202210064669A CN 114472896 A CN114472896 A CN 114472896A
- Authority
- CN
- China
- Prior art keywords
- tool blank
- brazing tool
- brazing
- sintering
- blank
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005219 brazing Methods 0.000 title claims abstract description 161
- 238000000034 method Methods 0.000 title claims abstract description 94
- 238000005728 strengthening Methods 0.000 title claims description 18
- 238000000137 annealing Methods 0.000 claims abstract description 62
- 238000005245 sintering Methods 0.000 claims abstract description 62
- 229910052751 metal Inorganic materials 0.000 claims abstract description 37
- 239000002184 metal Substances 0.000 claims abstract description 37
- 239000012768 molten material Substances 0.000 claims abstract description 7
- 238000002360 preparation method Methods 0.000 claims abstract description 6
- 239000000654 additive Substances 0.000 claims abstract description 4
- 230000000996 additive effect Effects 0.000 claims abstract description 4
- 230000003014 reinforcing effect Effects 0.000 claims abstract 2
- 239000013078 crystal Substances 0.000 claims description 28
- 238000001816 cooling Methods 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 15
- 229910003470 tongbaite Inorganic materials 0.000 claims description 14
- 239000007791 liquid phase Substances 0.000 claims description 13
- 238000009768 microwave sintering Methods 0.000 claims description 13
- 239000012071 phase Substances 0.000 claims description 13
- 238000007731 hot pressing Methods 0.000 claims description 12
- 238000004321 preservation Methods 0.000 claims description 12
- 238000002844 melting Methods 0.000 claims description 10
- 230000008018 melting Effects 0.000 claims description 10
- 239000007790 solid phase Substances 0.000 claims description 9
- 238000010892 electric spark Methods 0.000 claims description 5
- 238000003825 pressing Methods 0.000 claims description 4
- 239000002994 raw material Substances 0.000 claims description 4
- 238000009694 cold isostatic pressing Methods 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 239000000155 melt Substances 0.000 abstract description 5
- 238000002425 crystallisation Methods 0.000 abstract description 3
- 230000008025 crystallization Effects 0.000 abstract description 3
- 230000002035 prolonged effect Effects 0.000 abstract description 3
- 230000008569 process Effects 0.000 description 39
- 238000001953 recrystallisation Methods 0.000 description 14
- 239000000956 alloy Substances 0.000 description 9
- 229910045601 alloy Inorganic materials 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000000945 filler Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 238000005452 bending Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 238000000265 homogenisation Methods 0.000 description 4
- 238000011065 in-situ storage Methods 0.000 description 4
- 238000005482 strain hardening Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000001513 hot isostatic pressing Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910009043 WC-Co Inorganic materials 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 238000003763 carbonization Methods 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000003966 growth inhibitor Substances 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000005501 phase interface Effects 0.000 description 2
- 238000000678 plasma activation Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000005476 soldering Methods 0.000 description 2
- 238000002490 spark plasma sintering Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000007725 thermal activation Methods 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- 239000010953 base metal Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 239000004482 other powder Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/24—After-treatment of workpieces or articles
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0068—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
- C22C1/1036—Alloys containing non-metals starting from a melt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
- C22C1/1036—Alloys containing non-metals starting from a melt
- C22C1/1047—Alloys containing non-metals starting from a melt by mixing and casting liquid metal matrix composites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
- B22F2003/1054—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding by microwave
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/24—After-treatment of workpieces or articles
- B22F2003/248—Thermal after-treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F2005/002—Tools other than cutting tools
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Optics & Photonics (AREA)
- Composite Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention provides a brazing tool blank hardness reinforcing method, which comprises the following steps: s1: green body preparation, adding 2.5 wt% metal carbide additive to the molten material and holding → S2: green body sintering → S3: and continuously annealing the blank. According to the invention, the metal carbide is added when the brazing tool blank melts, so that the sintered brazing tool blank has excellent fire resistance, Brinell hardness and toughness, the strength and fire resistance of the brazing tool blank can be enhanced by adding the brazing tool blank sintered by the metal carbide, the service life is longer, the crystallization state of the brazing tool blank after continuous annealing is better, and the hardness is improved, so that the metal carbide is added into the brazing tool blank, and the brazing tool blank is continuously annealed in a continuous annealing manner, so that the strength and fire resistance of the brazing tool blank can be further improved, and the service life of the brazing tool blank is prolonged.
Description
Technical Field
The invention relates to the technical field of processing of brazing tools, in particular to a method for strengthening the hardness of a brazing tool blank.
Background
Brazing refers to a welding method for connecting metals by filling gaps of solid workpieces with liquid brazing filler metal after the brazing filler metal and the weldment which are lower than the melting point of the weldment are heated to the melting temperature of the brazing filler metal at the same time, wherein the brazing method comprises the steps of removing an oxide film and oil stains on the contact surface of a base metal to facilitate capillary tubes to play a role after the brazing filler metal is melted, increasing the wettability and capillary fluidity of the brazing filler metal, and the brazing is divided into brazing and soft soldering according to different melting points of the brazing filler metal;
the brazing process is that a flame gun is used for spraying high-temperature flame to melt and fill the brazing filler metal in an object so as to achieve the purpose of connecting or solidifying the object, and the head of the flame gun is a brazing tool and is mainly made of a brazing tool blank material.
The prior art has the following defects: the brazing tool is often used in a high-temperature environment (400-.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for strengthening the hardness of a brazing tool blank.
The invention solves the technical problems through the following technical means: a method of brazing tool blank hardness strengthening, the method of strengthening comprising the steps of:
s1: preparation of green bodies
Adding 12 wt% of Cr, 0.5 wt% of Ti, 2.5 wt% of W and 0.05 wt% of V into a high-temperature furnace for melting and mixing, adding 2.5 wt% of metal carbide additive into a molten material for heat preservation, and then pouring the molten material into a mold for cooling to obtain a brazing tool blank;
preferably, the metal carbide comprises VC, Cr3C2TaC and NbC;
preferably, wherein, VC and Cr3C2Is a common hard phase grain growth inhibitor, and a small amount of Cr is added3C2Can improve the strength and high-temperature oxidation resistance of a brazing tool blank, and 2 wt% of VC is added to the in-situ synthesisThe brazing tool blank body is sintered again, so that the growth of WC grains in a sintered body of the brazing tool blank body can be inhibited, the brazing tool blank body with the hard phase granularity of 65nm is prepared, and a WC/VC coherent phase interface is formed by adding VC, so that the migration of WC grain boundaries and the combined growth of WC grains are inhibited;
preferably, Cr is used3C2The carbon black and the VC powder are used as raw materials, metal carbide is prepared by adopting an in-situ reduction carbonization method and then is sintered by discharge plasma, and the average grain size of the brazing tool blank prepared finally is 101nm, and the brazing tool blank has high hardness and good toughness;
preferably, Cr3C2Has the most obvious effect of improving the corrosion resistance of a brazing tool blank, has the second best effect of VC, and is added with Cr3C2VC and rare earth La form a large amount of plate-shaped WC crystal grains with uniform size on a brazing tool blank after WC-Co sintering, the mechanical property is better, but VC and Cr are added3C2The refractory properties of the post-braze tool blank are reduced.
Preferably, TaC is a cubic crystal with density lower than WC, and has the characteristics of high melting point, large hardness and good wettability with Co, the high temperature of a brazing tool blank added with TaC is obviously improved, the microhardness of TaC at 400-1000 ℃ is higher than that of WC, and the high temperature hardness of the brazing tool blank can be improved by adding TaC in the brazing tool blank;
preferably, the brazing tool blank added with 2 wt% of TaC has obviously improved abrasion resistance, the added 2.5 wt% of TaC has the finest hard phase crystal grains and the highest hardness and strength, the content of TaC is further increased, the hard phase crystal grains are not refined any more, the excessive growth of WC crystal grains in the brazing tool blank can be effectively prevented by adding TaC into the brazing tool blank, and the bending strength of the brazing tool blank is high when the temperature of the brazing tool blank is higher than 800 ℃ after the TaC is added, but the toughness of the brazing tool blank is reduced after the TaC is added.
Preferably, Nb and Ta belong to the same group in the periodic table, so that NbC has the performance similar to that of TaC, the melting point is high, the hardness is high, the density is smaller than that of TaC, the wetting effect with a binder phase is better than that of TaC, the hardness and the bending strength of a brazing tool blank are obviously improved by adding NbC to prepare the brazing tool blank, and the fire resistance and the hardness of the hard alloy prepared by sintering through a PECS method are improved while the high toughness is maintained.
Preferably, by reacting VC and Cr3C2As a result of experimental studies on TaC and NbC, it was found that VC and Cr were added3C2Then, the overall strength and corrosion resistance of the brazing tool blank are increased, but the overall refractory properties of the brazing tool blank are poor, and after TaC is added, the overall strength and refractory properties of the brazing tool blank are increased, but toughness is poor and fracture is easy, and after NbC is added, the overall strength and refractory properties of the brazing tool blank are increased, and toughness is moderate, so NbC is preferably added to the melt as a metal carbide in this embodiment.
S2: sintering of the green body
Sintering the formed brazing tool blank, and constructing a sintered blank through three stages of heating, heat preservation and cooling;
preferably, the structural sintering comprises solid-phase sintering and subsequent HIP treatment, liquid-phase sintering, hot pressing, microwave sintering, electric spark sintering and the like;
preferably, the solid-phase sintering and the subsequent HIP treatment are carried out by pressing and molding a pressed compact with a component gradient or a hard phase grain size gradient, and the pressed compact is subjected to hot isostatic pressing after the solid-phase sintering;
preferably, the method is complex in process, low in production efficiency and not beneficial to large-scale industrial production, and adjacent layers of the compact are easy to generate homogenization due to atomic diffusion in the sintering process, so that gradient characteristics are weakened or even eliminated, and in addition, the hot isostatic pressing treatment adopted in the method is high in cost.
Preferably, the liquid phase sintering method heats the pressed blank with component gradient or grain size gradient to high enough temperature to enable the liquid phase to appear in the prefabricated block, the temperature is kept for a short time, and the temperature is reduced to below the liquid phase point before the tissue components are homogenized to complete the sintering;
preferably, the liquid phase sintering method is simplified in preparation process compared with solid phase sintering and subsequent HIP treatment, but the occurrence of liquid phase makes the alloy more easily homogenized in the sintering process, and the sintering characteristics are different due to different chemical compositions among different gradient layers in the pressed compact, so that internal stress is generated during sintering to cause deformation of the whole material.
Preferably, the green compact is subjected to hot-pressing sintering by a hot-pressing method, and a gradient structure brazing tool blank with higher density can be prepared in one step;
preferably, the hot-pressing sintering process is simplified and can be performed at a relatively low temperature, so that the homogenization process of the alloy in the sintering process is slow and easy to control, but the hot-pressing method cannot prepare a component with a complex shape.
Preferably, the microwave sintering method is to press a pressed blank with components distributed in a gradient manner by a cold isostatic pressing method, and then prepare a brazing tool blank with a gradient structure by microwave sintering in a pure Ar environment;
preferably, the microwave sintering is easy to control, safe, pollution-free, fast in temperature rise speed and short in sintering time, a new material and a new structure can be obtained in a selective heating mode, and in addition, the metallurgical and mechanical properties of the hard alloy are enhanced by the thermal activation and local heating of the WC crystal grains by microwaves.
Preferably, the electric spark sintering method is that metal powder and the like are filled into a graphite die, the upper die punch and the lower die punch of the die are used as electrified electrodes, pressure and pulse voltage are simultaneously applied to the powder, a temperature gradient can be formed in a sintered body through the graphite die with a gradient structure to realize gradient sintering, and a brazing tool blank with the gradient structure is prepared through discharge plasma activation, resistance heating and thermoplastic deformation.
Preferably, internal stresses due to different density and sintering densification speed at different locations within the gradient material are effectively eliminated, but similar to hot pressed sintering, this method does not allow the production of complex shaped components.
Preferably, in order to further improve the density, strength and refractory properties of the brazing tool blank itself, the present embodiment prefers a microwave sintering process as the structural sintering process of the brazing tool blank.
S3: annealing of the blank
Preferably, the adopted annealing process is recrystallization annealing, the brazing tool blank is heated to the temperature above the recrystallization temperature, and is cooled after being kept for a certain time, so that the brazing tool blank is recrystallized, and the deformed crystal grains are recrystallized into uniform equiaxial crystal grains, and the aim is to eliminate the deformation strengthening and the residual stress;
preferably, the metal microstructure is refined through recovery and recrystallization in the annealing process until the microstructure becomes fine and uniform equiaxial grains, the metal is removed from work hardening, the plasticity and the deformation capability of the brazing tool blank are recovered, the annealing process is a process for determining the comprehensive mechanical property of the brazing tool blank, the annealing temperature and the heat preservation time are the most important process parameters in the annealing process, and the two points have the greatest influence on the subsequent structure and the performance of the brazing tool blank;
preferably, the annealing temperature and the heat preservation time of the brazing tool blank are taken as the key research directions, and the change of the structure and the performance of the brazing tool blank is mainly carried out under different annealing temperatures and heat preservation times, so that the change rule is summarized, and the annealing process of the brazing tool blank is better formulated; the recrystallization conditions of the brazing tool blank are different under different annealing processes, and the recrystallization process of the brazing tool blank often has important influence on the structure and the performance of the brazing tool blank after annealing;
preferably, the recrystallization annealing includes hood annealing and continuous annealing;
preferably, the cover annealing is performed by placing the brazing tool blanks in a cover furnace in a stacking mode for annealing, wherein the heating mode comprises direct flame heating and indirect radiant tube heating, the cover furnace adopts two internal cooling modes of split flow or full flow, and the forced external cooling adopts a cooling cover;
preferably, the continuous annealing is that the brazing tool blank is annealed by an annealing furnace without a closed opening, and the brazing tool blank is not stopped in the middle;
preferably, under the hood-type annealing process, the crystal grains are firstly in a cake shape in the recrystallization process, then are gradually changed from the cake-shaped crystal grains to equiaxed crystal grains, and the continuous annealing enables the deformed crystal grains to be changed into uniform equiaxed crystal grains again, and meanwhile, the continuous annealing can also remove the work hardening and residual internal stress generated in the deformation process, and recover the structure and performance of the brazing tool blank to the state before cold deformation;
preferably, during continuous annealing, the brazing tool blank is placed into a high-temperature furnace, the temperature is raised to 600 ℃, annealing is continuously carried out for 30min, the temperature is raised to 800 ℃ at a speed of 80 ℃/h, heat preservation is carried out for 2h, and then water cooling is carried out to finish annealing treatment.
The invention has the beneficial effects that:
according to the invention, the metal carbide is added when the brazing tool blank melts, so that the sintered brazing tool blank has excellent fire resistance, Brinell hardness and toughness, the strength and fire resistance of the brazing tool blank can be enhanced by adding the brazing tool blank sintered by the metal carbide, the service life is longer, the crystallization state of the brazing tool blank after continuous annealing is better, and the hardness is improved, so that the metal carbide is added into the brazing tool blank, and the brazing tool blank is continuously annealed in a continuous annealing manner, so that the strength and fire resistance of the brazing tool blank can be further improved, and the service life of the brazing tool blank is prolonged.
Drawings
FIG. 1 is a flow chart of the operation of the present invention;
fig. 2 is a microstructure of an annealed brazing tool blank according to the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Example 1
Referring to fig. 1, the method for strengthening the hardness of a brazing tool blank according to the embodiment includes the following steps:
s1: preparation of green bodies
Adding 12 wt% of Cr, 0.5 wt% of Ti, 2.5 wt% of W and 0.05 wt% of V into a high-temperature furnace for melting and mixing, adding 2.5 wt% of metal carbide additive into a molten material for heat preservation, and then pouring the molten material into a mold for cooling to obtain a brazing tool blank;
the metal carbide includes VC and Cr3C2TaC and NbC;
wherein, VC and Cr3C2Is a common hard phase grain growth inhibitor, and a small amount of Cr is added3C2The strength and high-temperature oxidation resistance of a brazing tool blank can be improved, 2 wt% of VC is added into the in-situ synthesized brazing tool blank and then sintered to inhibit the growth of WC grains in a sintered body of the brazing tool blank, so that the brazing tool blank with the hard phase granularity of 65nm is prepared, and a WC/VC coherent phase interface is formed by adding the VC, so that the migration of WC grain boundaries and the combined growth of WC grains are inhibited;
with Cr3C2The carbon black and the VC powder are used as raw materials, metal carbide is prepared by adopting an in-situ reduction carbonization method and then is sintered by discharge plasma, and the average grain size of the brazing tool blank prepared finally is 101nm, and the brazing tool blank has high hardness and good toughness;
Cr3C2has the most obvious effect of improving the corrosion resistance of a brazing tool blank, has the second best effect of VC, and is added with Cr3C2VC and rare earth La form a large amount of plate-shaped WC crystal grains with uniform size on a brazing tool blank after WC-Co sintering, and the brazing tool blank has better performanceMechanical properties, but adding VC and Cr3C2The refractory properties of the post-braze tool blank are reduced.
TaC is a cubic crystal with density lower than WC, and has the characteristics of high melting point, large hardness and good wettability with Co, the high temperature of a brazing tool blank added with the TaC is obviously improved, the microhardness of the TaC at 400-plus-one 1000 ℃ is higher than that of WC, and the high temperature hardness of the brazing tool blank can be improved by adding the TaC into the brazing tool blank;
the brazing tool blank added with 2 wt% of TaC has obviously improved abrasion resistance, when the addition amount of 2.5 wt% of TaC is that the hard phase crystal grains are finest, the hardness and the strength are highest, and the content of TaC is further increased, the hard phase crystal grains are not refined any more, the excessive growth of WC crystal grains in the brazing tool blank can be effectively prevented by adding the TaC into the brazing tool blank, and when the temperature of the brazing tool blank is higher than 800 ℃ after the TaC is added, the bending strength of the brazing tool blank is high, but the toughness of the brazing tool blank is reduced after the TaC is added.
Nb and Ta belong to the same group in the periodic table of elements, so that the performance of NbC is similar to that of TaC, the melting point is high, the hardness is high, the density is lower than that of TaC, the wetting effect with a binding phase is better than that of TaC, the hardness and the bending strength of a brazing tool blank are obviously improved by adding NbC to prepare the brazing tool blank, and the fire resistance and the hardness of the brazing tool blank are improved while the high toughness of the hard alloy prepared by sintering through a PECS method is maintained.
By the pair of VC and Cr3C2As a result of experimental studies on TaC and NbC, it was found that VC and Cr were added3C2Then, the overall strength and corrosion resistance of the brazing tool blank are increased, but the overall refractory properties of the brazing tool blank are poor, and after TaC is added, the overall strength and refractory properties of the brazing tool blank are increased, but toughness is poor and fracture is easy, and after NbC is added, the overall strength and refractory properties of the brazing tool blank are increased, and toughness is moderate, so NbC is preferably added to the melt as a metal carbide in this embodiment.
S2: sintering of the green body
Sintering the formed brazing tool blank, and constructing a sintered blank through three stages of heating, heat preservation and cooling;
the structural sintering comprises solid-phase sintering and subsequent HIP treatment, a liquid-phase sintering method, a hot pressing method, a microwave sintering method, an electric spark sintering method and the like;
wherein, the solid phase sintering and the subsequent HIP treatment are used for pressing and forming a pressed compact with a component gradient or a hard phase granularity gradient, and the pressed compact is subjected to hot isostatic pressing treatment after the solid phase sintering;
however, the method has complex process and low production efficiency, is not beneficial to realizing large-scale industrial production, and the adjacent layers of the pressed block are easy to generate homogenization due to atomic diffusion in the sintering process, so that the gradient characteristic is weakened or even disappears.
The liquid phase sintering method heats the pressed blank with component gradient or grain size gradient to high enough temperature to enable the prefabricated block to generate liquid phase, the temperature is kept for a short time, and the temperature is reduced to below the liquid phase point before the organization components are homogenized to complete the sintering;
compared with solid-phase sintering and subsequent HIP treatment methods, the liquid-phase sintering method has the advantages that the preparation process is simplified, however, the occurrence of a liquid phase enables the alloy to be more easily homogenized in the sintering process, the sintering characteristics of the alloy are different due to different chemical compositions among different gradient layers in a pressed blank, and the deformation of the whole material can be caused by internal stress generated during sintering.
Carrying out hot-pressing sintering on the pressed compact by a hot-pressing method, and preparing a soldering tool blank with a gradient structure with higher density by one step;
the hot-pressing sintering process is simplified and can be carried out at a relatively low temperature, so that the homogenization process of the alloy in the sintering process is slow and is easy to control, but the hot-pressing method cannot prepare components with complex shapes.
The microwave sintering method comprises the steps of firstly pressing a pressed blank with components distributed in a gradient manner by a cold isostatic pressing method, and then preparing a brazing tool blank with a gradient structure by microwave sintering in a pure Ar environment;
the microwave sintering is easy to control, safe, pollution-free, fast in temperature rise speed and short in sintering time, new materials and new structures can be obtained in a selective heating mode, and in addition, the metallurgical and mechanical properties of the hard alloy are enhanced through thermal activation and local heating of WC crystal grains by microwaves.
The electric spark sintering method is that metal powder and other powder are filled into a graphite die, the upper die punch and the lower die punch of the die are used as electrified electrodes, pressure and pulse voltage are simultaneously applied to the powder, a temperature gradient can be formed in a sintered body through the graphite die with a gradient structure to realize gradient sintering, and a brazing tool blank with a gradient structure is prepared through discharge plasma activation, resistance heating and thermoplastic deformation.
The internal stress caused by different density and sintering densification speed of different parts in the gradient material can be effectively eliminated, but similar to the hot pressing sintering method, the method cannot prepare the component with a complex shape.
In view of the above, in order to further improve the density, strength and fire resistance of the brazing tool blank itself, the present embodiment preferably employs a microwave sintering method as the structural sintering treatment of the brazing tool blank.
S3: annealing of the blank
The annealing process adopted in the embodiment is recrystallization annealing, the brazing tool blank is heated to the temperature above the recrystallization temperature, and is cooled after being kept for a certain time, so that the brazing tool blank is recrystallized, and the deformed crystal grains are recrystallized into uniform equiaxial crystal grains, and the aim of eliminating deformation strengthening and residual stress is fulfilled;
refining a metal microstructure through recovery and recrystallization in the annealing process until the microstructure becomes fine and uniform equiaxial grains, removing metal work hardening, and recovering the plasticity and the deformation capability of a brazing tool blank;
therefore, the annealing temperature and the heat preservation time of the brazing tool blank are taken as the key research directions, and the change of the structure and the performance of the brazing tool blank is mainly under different annealing temperatures and heat preservation times, so that the change rule is summarized, and the annealing process of the brazing tool blank is better formulated; the recrystallization conditions of the brazing tool blank are different under different annealing processes, and the recrystallization process of the brazing tool blank often has important influence on the structure and the performance of the brazing tool blank after annealing;
the recrystallization annealing comprises cover annealing and continuous annealing;
wherein, the cover annealing is to place the brazing tool blank in a cover furnace in a stacking mode for annealing, the heating mode comprises direct flame heating and indirect radiant tube heating, the cover furnace adopts two internal cooling modes of split flow or full flow, and the forced external cooling adopts a cooling cover;
continuous annealing is to anneal the brazing tool blank through an annealing furnace without a closed opening, and the brazing tool blank is not stopped in the middle;
under the cover annealing process, the crystal grains are firstly in a cake shape in the recrystallization process and then gradually changed from the cake-shaped crystal grains to equiaxial crystal grains, and the continuous annealing enables the deformed crystal grains to be changed into uniform equiaxial crystal grains again, and simultaneously, the continuous annealing can also remove the work hardening and residual internal stress generated in the deformation process, and recover the structure and the performance of the brazing tool blank to the state before cold deformation;
during continuous annealing, the brazing tool blank is placed into a high-temperature furnace, the temperature is increased to 600 ℃, the continuous annealing is carried out for 30min, the temperature is increased to 800 ℃ at a speed of 80 ℃/h, the temperature is kept for 2h, then the annealing treatment is completed by water cooling, and the structure appearance of the brazing tool blank is observed by a scanning electron microscope after the annealing as shown in figure 2.
Comparative example 1
This comparative example differs from example 1 in that no metal carbide was added.
Comparative example 2
The difference between the comparative example and the example 1 is that a cover annealing process is adopted when the blank body is annealed.
Example 2
This example tests the brazing tool blanks of example 1, comparative example 1 and comparative example 2 for fire resistance, brinell hardness and toughness, respectively, and the results are shown in table 1:
TABLE 1
As can be seen from the above table, in the embodiment of the present invention, metal carbide is added when a brazing tool blank melts, so that the sintered brazing tool blank has superior fire resistance, brinell hardness and toughness, compared with the case where metal carbide is not added in comparative example 1, the brazing tool blank added with metal carbide sintering can enhance the strength and fire resistance of the brazing tool blank, and has a longer service life, and compared with the case annealing process adopted when the blank in comparative example 2 is annealed, the brazing tool blank after continuous annealing has a better crystallization state and improved hardness, so that the metal carbide is added to the brazing tool blank, and the brazing tool blank is continuously annealed by a continuous annealing mode, so that the strength and fire resistance of the brazing tool blank can be further improved, and the service life of the brazing tool blank can be prolonged.
It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. The method for strengthening the hardness of the brazing tool blank is characterized by comprising the following steps: the reinforcing method comprises the following steps:
s1: preparation of green bodies
Adding the raw materials into a high-temperature furnace for melting and mixing, adding a metal carbide additive into a molten material for heat preservation, and then pouring the molten material into a mold for cooling to obtain a brazing tool blank;
s2: sintering of the green body
Sintering the formed brazing tool blank, and constructing a sintered blank through three stages of heating, heat preservation and cooling;
s3: annealing of the blank
And continuously annealing the sintered brazing tool blank through a high-temperature furnace.
2. A method of hardness strengthening of a brazing tool blank according to claim 1, characterised in that: in step S1, the metal carbide includes VC and Cr3C2TaC and NbC.
3. A method of hardness strengthening of a brazing tool blank according to claim 2, characterised in that: the VC and the Cr are3C2Inhibiting the growth of WC grains in a sintered body of a brazing tool blank after the addition of the Cr3C2After the addition, a large amount of plate-shaped WC crystal grains with uniform size are formed in the brazing tool blank.
4. A method of hardness strengthening of a brazing tool blank according to claim 3, characterised in that: after the TaC and the NbC are added, the growth of WC crystal grains in the brazing tool blank is inhibited, and the bonding phase of the NbC and the brazing tool blank is wetted.
5. A method of hardness strengthening of a brazing tool blank according to claim 1, characterised in that: in the step S1, the raw materials include 12-14 wt% of Cr, 0.5-0.8 wt% of Ti, 2.5-3 wt% of W and 0.05-0.08 wt% of V.
6. A method of hardness strengthening of a brazing tool blank according to claim 5, characterised in that: in the step S1, the addition amount of the metal carbide is 2.5-3 wt%.
7. A method of hardness strengthening of a brazing tool blank according to claim 1, characterised in that: in step S2, the structural sintering includes solid-phase sintering and subsequent HIP treatment, liquid-phase sintering, hot-pressing, microwave sintering, and electric spark sintering.
8. A method of strengthening the hardness of a brazing tool blank according to claim 7, wherein: the microwave sintering method comprises the steps of firstly pressing a pressed blank with components distributed in a gradient manner by a cold isostatic pressing method, and then preparing a brazing tool blank with a gradient structure by microwave sintering in a pure Ar environment.
9. A method of hardness strengthening of a brazing tool blank according to claim 1, characterised in that: in the step S3, during continuous annealing, the temperature is raised to 600 ℃ for continuous annealing for 30min, the temperature is raised to 800 ℃ at a speed of 80 ℃/h, the temperature is kept for 2h, and then the annealing treatment is completed by water cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210064669.1A CN114472896B (en) | 2022-01-20 | 2022-01-20 | Method for reinforcing hardness of brazing tool blank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210064669.1A CN114472896B (en) | 2022-01-20 | 2022-01-20 | Method for reinforcing hardness of brazing tool blank |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114472896A true CN114472896A (en) | 2022-05-13 |
| CN114472896B CN114472896B (en) | 2023-12-12 |
Family
ID=81472088
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210064669.1A Active CN114472896B (en) | 2022-01-20 | 2022-01-20 | Method for reinforcing hardness of brazing tool blank |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114472896B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118788971A (en) * | 2024-09-12 | 2024-10-18 | 中国民用航空飞行学院 | A preparation system for functional gradient materials |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5841045A (en) * | 1995-08-23 | 1998-11-24 | Nanodyne Incorporated | Cemented carbide articles and master alloy composition |
| CN102605273A (en) * | 2012-04-11 | 2012-07-25 | 长沙威斯坦冶金制品有限公司 | Steel bonded hard alloy and preparation method thereof |
| CN102776446A (en) * | 2012-08-15 | 2012-11-14 | 安徽嘉龙锋钢刀具有限公司 | Semi-high speed steel copper soldering inlaid steel cutting blade and manufacturing method thereof |
| CN103752816A (en) * | 2013-12-28 | 2014-04-30 | 扬州立德粉末冶金股份有限公司 | Gasoline engine exhaust valve seat and preparing method thereof |
| US20150143953A1 (en) * | 2013-06-21 | 2015-05-28 | National Tsing Hua University | Refractory metal matrix-ceramic compound multi-component composite material with super-high melting point |
| CN106222475A (en) * | 2016-08-29 | 2016-12-14 | 河源富马硬质合金股份有限公司 | A kind of preparation method of Large scale alloy |
| CN109824363A (en) * | 2017-11-23 | 2019-05-31 | 陈瑞凯 | Tough ceramic material |
| CN110629125A (en) * | 2018-06-25 | 2019-12-31 | 上海梅山钢铁股份有限公司 | Cold-rolled steel plate with excellent aging resistance for continuous brazing type double-layer coil-welded pipe |
| CN111101048A (en) * | 2018-10-25 | 2020-05-05 | 青海民族大学 | In-situ TaC particle and iron-based amorphous alloy synergistically reinforced medium-high manganese steel-based composite material and preparation method thereof |
-
2022
- 2022-01-20 CN CN202210064669.1A patent/CN114472896B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5841045A (en) * | 1995-08-23 | 1998-11-24 | Nanodyne Incorporated | Cemented carbide articles and master alloy composition |
| CN102605273A (en) * | 2012-04-11 | 2012-07-25 | 长沙威斯坦冶金制品有限公司 | Steel bonded hard alloy and preparation method thereof |
| CN102776446A (en) * | 2012-08-15 | 2012-11-14 | 安徽嘉龙锋钢刀具有限公司 | Semi-high speed steel copper soldering inlaid steel cutting blade and manufacturing method thereof |
| US20150143953A1 (en) * | 2013-06-21 | 2015-05-28 | National Tsing Hua University | Refractory metal matrix-ceramic compound multi-component composite material with super-high melting point |
| CN103752816A (en) * | 2013-12-28 | 2014-04-30 | 扬州立德粉末冶金股份有限公司 | Gasoline engine exhaust valve seat and preparing method thereof |
| CN106222475A (en) * | 2016-08-29 | 2016-12-14 | 河源富马硬质合金股份有限公司 | A kind of preparation method of Large scale alloy |
| CN109824363A (en) * | 2017-11-23 | 2019-05-31 | 陈瑞凯 | Tough ceramic material |
| CN110629125A (en) * | 2018-06-25 | 2019-12-31 | 上海梅山钢铁股份有限公司 | Cold-rolled steel plate with excellent aging resistance for continuous brazing type double-layer coil-welded pipe |
| CN111101048A (en) * | 2018-10-25 | 2020-05-05 | 青海民族大学 | In-situ TaC particle and iron-based amorphous alloy synergistically reinforced medium-high manganese steel-based composite material and preparation method thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118788971A (en) * | 2024-09-12 | 2024-10-18 | 中国民用航空飞行学院 | A preparation system for functional gradient materials |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114472896B (en) | 2023-12-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH04232234A (en) | Production of product from doping material containing alloy on basis of titanium aluminide | |
| US2206395A (en) | Process for obtaining pure chromium, titanium, and certain other metals and alloys thereof | |
| CN102449176A (en) | Method for producing beta-gamma-TiAl-based alloy | |
| CN101921922B (en) | Manufacturing method of magnesium alloy and magnesium alloy | |
| CN1962179A (en) | Direct rolling of cast gamma titanium aluminide alloys | |
| WO2021046927A1 (en) | Nickel-rhenium alloy rotary tubular target material containing trace rare earth elements and preparation method therefor | |
| JP4415303B2 (en) | Sputtering target for thin film formation | |
| CN111926232A (en) | High-entropy alloy material and preparation method thereof | |
| CN113881875A (en) | A kind of three-dimensional skeleton structure metal reinforced aluminum matrix composite material and preparation method | |
| CN113215494B (en) | Preparation method of aviation invar alloy plate | |
| CN110484757A (en) | A kind of high conductivity and heat heat resistance in-situ authigenic aluminum matrix composite and preparation method | |
| CN114472896B (en) | Method for reinforcing hardness of brazing tool blank | |
| CN100441363C (en) | A kind of high-temperature brazing alloy solder for welding ceramics and steel and preparation method thereof | |
| CN110423904B (en) | A method for preparing Ni-Cr-Co-Fe-Mn high-entropy alloy by homogenization and high purification by electron beam melting | |
| CN114892064A (en) | FeCrCuVCo high-entropy alloy and preparation method thereof | |
| CN116607028B (en) | Smelting method of refractory high-entropy alloy | |
| CN1081242C (en) | Process for preparing TiNi-base marmem directly from elements powder | |
| CN110670037A (en) | Preparation method for FeAlCoCuNiV high-entropy alloy target material through hot isostatic pressing | |
| CN113322388B (en) | Preparation method of high-Mo titanium alloy ingot | |
| CN109735757A (en) | A kind of sintered hard alloy boat contact material | |
| CN110484742B (en) | A method for preparing Fe-W master alloy with high purification by electron beam melting | |
| CN112296606B (en) | Preparation method of vacuum centrifugal TiAl intermetallic compound plate | |
| CN115502399A (en) | A method for preparing titanium-based composite material by low-temperature hot isostatic pressing and the titanium-based composite material prepared thereby | |
| CN114427046A (en) | Short-process preparation device and preparation method of alloy | |
| CN118600257B (en) | Recycling method of rhenium-containing superalloy powder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |