Method and device for manufacturing light alloy grains by using induction-assisted shot blasting to refine laser additive
Technical Field
The invention relates to the technical field of laser additive manufacturing, laser cladding and laser thermal spraying, in particular to a method and a device for manufacturing light alloy grains by using induction-assisted shot blasting to refine laser additives.
Background
Most of core key parts of modern high-end equipment are moving parts, and frequent damage and even failure of the core key parts are caused by abrasion, corrosion, fatigue and the like, so that the long-term reliable operation of equipment is threatened, and a large amount of expensive core key parts are scrapped, thereby causing huge economic loss, resource waste and energy waste.
With the continuous progress and development of aerospace technology, the demand and quality requirements for high-performance materials are further improved, and taking the most representative titanium alloy in light alloys as an example, the titanium alloy has a series of excellent performance characteristics such as high specific strength, good corrosion resistance, high temperature resistance and the like, and is widely applied to the aerospace field.
The laser additive manufacturing technology has the advantages that the direct forming of complex parts is realized, the mechanical property of the formed parts is equivalent to that of a forged piece, and the laser additive manufacturing technology is the optimal choice for processing and manufacturing titanium alloy parts in the fields of aerospace, biomedical use and the like. According to the forming theory of laser additive manufacturing titanium alloy, in the laser forming process, a large temperature gradient (Z direction) from top to bottom exists between a molten pool and a substrate, and a temperature gradient (X direction) from inside to outside also exists in the horizontal direction of the molten pool. Under the temperature field, the molten pool is instantly solidified to form coarse columnar crystals penetrating through a plurality of cladding layers along the direction of temperature gradient, and finally the problems of poor comprehensive mechanical property, outstanding anisotropy and the like of a formed part are caused.
Disclosure of Invention
The invention provides a method and a device for manufacturing light alloy crystal grains by induction-assisted shot peening and thinning laser additive, which can be used for strengthening and promoting the spheroidization process of a structure by adopting shot peening at high temperature, thinning the alloy crystal grains, blocking columnar crystals from penetrating through a cladding layer and growing in an unlimited extension manner along the forming height direction, so that a uniformly-thinned near-equiaxial crystal structure is obtained inside a light alloy forming part, the comprehensive mechanical property of a light alloy component manufactured by laser additive is improved, and the anisotropy is weakened.
The specific technical scheme provided by the invention is as follows:
on one hand, the device for manufacturing the light alloy crystal grains by using the induction-assisted shot blasting, thinning and laser additive comprises a closed processing cabin, a base body positioned in the closed processing cabin, a first induction coil arranged around a cladding layer above the base body, an infrared temperature measuring device positioned above the cladding layer, a converter positioned in the closed processing cabin, and a Laval nozzle and a laser cladding head which are oppositely arranged on two sides of the converter, wherein a second induction coil is arranged in the circumferential direction of an outlet of the Laval nozzle, the Laval nozzle and the laser cladding head are alternately arranged above the cladding layer by switching the converter, and the outlet temperature of the Laval nozzle is controlled to be 800-930 ℃ by the second induction coil.
Optionally, the second induction coil is fixed in a circumferential direction of an outlet of the laval nozzle, and the second induction coil rotates around the converter together with the laval nozzle.
Optionally, the second induction coil is used for heating metal shot blasting and carrier gas to realize high-temperature shot blasting strengthening treatment at 850-900 ℃.
Optionally, a center line of the first induction coil is flush with an upper surface of the cladding layer, and the converter rotates clockwise by 180 ° to realize the switching of the working positions of the laval nozzle and the laser cladding head.
In another aspect, the present invention also provides a method for manufacturing light alloy crystal grains by using induction-assisted shot peening laser additive manufacturing, wherein the method uses the above-mentioned apparatus for manufacturing light alloy crystal grains by using induction-assisted shot peening laser additive manufacturing, and the method includes:
step 1: moving a laser cladding head to a position right above a base body by rotating a converter clockwise, and starting a first induction coil to heat the base body to 850-900 ℃;
step 2: adjusting the position of an infrared temperature measuring device to enable temperature measuring light spots formed by the infrared temperature measuring device to be located on the surface of the forming position of the surface of the base body;
and step 3: opening the laser cladding head to prepare a cladding layer on the surface of the substrate by adopting a laser additive manufacturing method, wherein the thickness of the cladding layer is 0.03-3 mm, and the cladding layer is made of titanium-aluminum alloy;
and 4, step 4: rotating the converter clockwise by 180 degrees, rotating the Laval nozzle to the position above the cladding layer, and starting a second induction coil to heat the metal shot blasting and the carrier gas in the Laval nozzle to a high temperature of 850-900 ℃;
and 5: opening the Laval nozzle to perform high-temperature shot peening strengthening treatment on the cladding layer, wherein the first induction coil is kept in an open state in the high-temperature shot peening strengthening treatment process so as to maintain the temperature of the substrate and the cladding layer to be always kept above 850 ℃ in the high-temperature shot peening strengthening treatment process;
step 6: and (3) lifting the infrared temperature measuring device, the first induction coil and the converter by the height of a cladding layer, and then repeating the steps 1 to 5 to mold the next cladding layer and perform high-temperature shot peening strengthening treatment until the whole light alloy part is molded.
Optionally, the light alloy part is made of titanium alloy, aluminum alloy or magnesium alloy.
The invention has the following beneficial effects:
the embodiment of the invention provides a device for manufacturing light alloy crystal grains by using induction-assisted shot blasting, refining and laser additive materials, which comprises a closed processing cabin, a base body, a first induction coil, an infrared temperature measuring device, a converter, a Laval nozzle and a laser cladding head, wherein the base body is positioned in the closed processing cabin, the first induction coil is arranged around a cladding layer above the base body, the infrared temperature measuring device is positioned above the cladding layer, the converter is positioned in the closed processing cabin, and the Laval nozzle and the laser cladding head are oppositely arranged on two sides of the converter; furthermore, in the laser additive manufacturing process, laser cladding additive manufacturing under high-temperature shot peening strengthening treatment can be realized by adopting a set of system through a rotary converter, in the laser cladding additive manufacturing process, shot peening treatment is realized by adopting a set of equipment to be matched with high-temperature shot peening strengthening treatment under induction heating, internal structure defects of the light alloy are effectively eliminated, the spheroidizing process of the structure is promoted, alloy grains are refined, the fatigue strength is improved, the mechanical property of the alloy is improved, and the columnar grains are prevented from penetrating through a cladding layer and growing in an unlimited extension mode along the forming height direction, so that the inside of a light alloy formed part is enabled to obtain a uniformly refined near-isometric crystal structure, and the anisotropy is weakened; and the induction heating is kept to 700-950 ℃ in the shot blasting process, and meanwhile, the induction coil is used for heating the shot blasting carrier gas in the shot blasting process so as to further improve the action strength and depth of shot blasting and shorten the shot blasting time.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an apparatus for manufacturing light alloy grains by using an induction-assisted laser additive process for shot peening;
fig. 2 is a schematic structural diagram of an apparatus for manufacturing light alloy grains by using an induction-assisted laser additive process for shot peening according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. 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.
An apparatus and a method for manufacturing light alloy crystal grains by using an induction-assisted shot peening laser additive manufacturing method according to an embodiment of the present invention will be described in detail with reference to fig. 1 to 2.
Referring to fig. 1 and 2, an apparatus for manufacturing light alloy crystal grains by using induction-assisted shot blasting to refine laser additive materials according to an embodiment of the present invention includes a closed processing chamber 8, a substrate 1 located inside the closed processing chamber 8, a first induction coil 3 disposed around a cladding layer 4 above the substrate 1, an infrared temperature measuring device 2 located above the cladding layer 4, a converter 7 located inside the closed processing chamber 8, and a laval nozzle 6 and a laser cladding head 5 disposed on two sides of the converter 7, where a second induction coil 9 is disposed in a circumferential direction at an outlet of the laval nozzle 6, the laval nozzle 6 and the laser cladding head 5 can alternately appear above the cladding layer 4 by switching the converter 7, and the second induction coil 9 controls an outlet temperature of the laval nozzle 6 to be 800 ℃ to 930 ℃.
Referring to fig. 1 and 2, the laval nozzle 6 and the laser cladding head 5 are symmetrically fixed on both sides of the converter 7, and the converter 7 rotates clockwise 180 degrees to realize the exchange of the working positions of the laval nozzle 6 and the laser cladding head 5. That is in the laser cladding additive manufacturing process, through rotary converter 7 and then can adopt a set of processing equipment to realize the in-process of laser cladding at a station and carry out high temperature shot peening strengthening treatment, and, can adopt same set of induction heating device to carry out induction heating to the work piece in high temperature shot peening strengthening treatment and the laser cladding process, realize that the work piece is in the heating state all the time in high temperature shot peening strengthening treatment process, adopt the converter to realize that the work piece does not need to change and equipment is changed between two processes of laser cladding and high temperature shot peening strengthening treatment, only rotary converter can realize whole course of working, not only machining efficiency is high and operational reliability is strong.
Referring to fig. 1 and 2, the second induction coil 9 is fixed in the circumferential direction at the outlet of the laval nozzle 6, and the second induction coil 9 rotates around the converter 7 together with the laval nozzle 6. The second induction coil 9 is used for heating metal shot blasting and carrier gas to realize high-temperature shot blasting strengthening treatment at 850-900 ℃. The center line of the first induction coil 3 is flush with the upper surface of the cladding layer 4.
On the other hand, the embodiment of the invention is based on the same inventive concept, and further provides a method for manufacturing light alloy crystal grains by using induction-assisted shot peening laser additive manufacturing, wherein the method adopts the device for manufacturing light alloy crystal grains by using induction-assisted shot peening laser additive manufacturing, and the method comprises the following steps:
step 1: moving a laser cladding head to a position right above a base body by rotating a converter clockwise, and starting a first induction coil to heat the base body to 850-900 ℃;
step 2: adjusting the position of an infrared temperature measuring device to enable temperature measuring light spots formed by the infrared temperature measuring device to be located on the surface of the forming position of the surface of the base body;
and step 3: opening the laser cladding head to prepare a cladding layer on the surface of the substrate by adopting a laser additive manufacturing method, wherein the thickness of the cladding layer is 0.03-3 mm, and the cladding layer is made of titanium-aluminum alloy;
and 4, step 4: rotating the converter clockwise by 180 degrees, rotating the Laval nozzle to the position above the cladding layer, and starting a second induction coil to heat the metal shot blasting and the carrier gas in the Laval nozzle to a high temperature of 850-900 ℃;
and 5: opening the Laval nozzle to perform high-temperature shot peening strengthening treatment on the cladding layer, wherein the first induction coil is kept in an open state in the high-temperature shot peening strengthening treatment process so as to maintain the temperature of the substrate and the cladding layer to be always kept above 850 ℃ in the high-temperature shot peening strengthening treatment process;
step 6: and (3) lifting the infrared temperature measuring device, the first induction coil and the converter by the height of a cladding layer, and then repeating the steps 1 to 5 to mold the next cladding layer and perform high-temperature shot peening strengthening treatment until the whole light alloy part is molded. Wherein, the light alloy parts are made of titanium alloy, aluminum alloy or magnesium alloy.
Specifically, in the working process of the Laval nozzle 6, the scanning speed of a shot blasting spray gun is 12-68mm/s, the pressure of shot blasting gas is 1.8-4.2MPa, the spray gun adopts a Laval tube with the length of 150-450mm, the shot blasting distance is 20-30mm, the powder feeding speed is 20-45g/min, the shot blasting time is 30-100s, and the temperature of shot blasting carrier gas is 850-900 ℃.
According to the method for manufacturing the light alloy crystal grains by the induction-assisted shot blasting and thinning laser additive manufacturing, the cladding layer is heated through the induction coil, then the formed cladding layer is subjected to high-temperature shot blasting strengthening treatment through the rotary converter by adopting the Laval nozzle, metal shot blasting and carrier gas are heated by adopting the induction coil so as to improve the depth of shot blasting action, improve the shot blasting effect, prevent columnar crystals from penetrating through the cladding layer and growing in an unlimited extension manner along the forming height direction, so that a uniformly-thinned near-isometric crystal structure is obtained inside a formed part of the light alloy, the anisotropy is weakened, the comprehensive mechanical property of the formed part is improved, a guiding effect is provided for the direct laser forming and repairing of the light alloy part, and obvious economic benefits are brought to the field of preparing the light alloy (especially titanium alloy) by the laser additive manufacturing.
According to the method for manufacturing the light alloy crystal grains by the induction-assisted shot blasting, shot blasting and induction heating are adopted to realize shot blasting strengthening treatment at high temperature, the first induction coil is always in a heating state in the shot blasting treatment and laser cladding processes through the converter, the internal structure defects of the light alloy are effectively eliminated, the structure spheroidization process is promoted, the alloy crystal grains are refined, the fatigue strength is improved, the mechanical property of the alloy is improved, the columnar crystals are prevented from penetrating through a cladding layer and growing in an unlimited extension mode along the forming height direction, and the inside of a light alloy formed part is enabled to obtain a uniformly refined near-isometric crystal structure, so that the anisotropy is weakened; in addition, the metal shot blasting and the carrier gas are kept to be inductively heated to the high temperature of 850-900 ℃ in the shot blasting process, and meanwhile, the shot blasting carrier gas is heated by adopting an induction coil in the shot blasting process so as to further improve the action strength and depth of the shot blasting and shorten the shot blasting time.
According to the method for manufacturing the light alloy crystal grains by the induction-assisted shot blasting and thinning laser additive, the induction heating coil is arranged at the nozzle of the laval nozzle for shot blasting, so that metal shot blasting sprayed out from the nozzle can be inductively heated, and further, shot blasting carrier gas is heated by the induction coil in the shot blasting process, so that the action strength and the depth of the shot blasting are further improved, and the shot blasting time is shortened. In addition, according to the device for manufacturing the light alloy crystal grains by the induction-assisted shot blasting, thinning and laser additive manufacturing, station switching of the laser head 5 and the laval nozzle 6 is realized by arranging the converter 7, induction heating of the same induction coil in the processes of spraying and shot blasting can be realized only by rotating the converter 7, and the induction coil arranged outside the laval nozzle 6 and the induction coil arranged on the periphery of a workpiece are matched with each other to heat shot blasting carrier gas by the induction coil in the process of shot blasting so as to further improve the shot blasting action intensity and depth and shorten the shot blasting time.
The embodiment of the invention provides a device for manufacturing light alloy crystal grains by using induction-assisted shot blasting, refining and laser additive materials, which comprises a closed processing cabin, a base body, a first induction coil, an infrared temperature measuring device, a converter, a Laval nozzle and a laser cladding head, wherein the base body is positioned in the closed processing cabin, the first induction coil is arranged around a cladding layer above the base body, the infrared temperature measuring device is positioned above the cladding layer, the converter is positioned in the closed processing cabin, and the Laval nozzle and the laser cladding head are oppositely arranged on two sides of the converter; furthermore, in the laser additive manufacturing process, laser cladding additive manufacturing under high-temperature shot peening strengthening treatment can be realized by adopting a set of system through a rotary converter, in the laser cladding additive manufacturing process, shot peening treatment is realized by adopting a set of equipment to be matched with high-temperature shot peening strengthening treatment under induction heating, internal structure defects of the light alloy are effectively eliminated, the spheroidizing process of the structure is promoted, alloy grains are refined, the fatigue strength is improved, the mechanical property of the alloy is improved, and the columnar grains are prevented from penetrating through a cladding layer and growing in an unlimited extension mode along the forming height direction, so that the inside of a light alloy formed part is enabled to obtain a uniformly refined near-isometric crystal structure, and the anisotropy is weakened; and the induction heating is kept to 700-950 ℃ in the shot blasting process, and meanwhile, the induction coil is used for heating the shot blasting carrier gas in the shot blasting process so as to further improve the action strength and depth of shot blasting and shorten the shot blasting time.
It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to encompass such modifications and variations.