CN106927848A - A kind of Zirconium Diboride-based Ultra-high Temperature Ceramics welding point and preparation method thereof - Google Patents

Abstract

The invention relates to a zirconium diboride-based ultra-high temperature ceramic welded joint and a preparation method thereof. The zirconium diboride-based ultra-high temperature ceramic welded joint includes at least two zirconium diboride-based ultra-high temperature ceramic substrates and two An ultra-high-temperature solder layer between the zirconium diboride-based ultra-high-temperature ceramic substrates, wherein there is an interfacial reaction layer formed by mutual penetration between the zirconium diboride-based ultra-high-temperature ceramic substrates and the high-temperature solder layer, and the high-temperature The chemical composition of the solder layer is Ni _1-xy A _x B _y , where A is at least one of molybdenum and chromium, and B is at least one of tungsten, cobalt, iron, zirconium and titanium, 0<x≤0.6, 0≤y≤0.25.

Description

A zirconium diboride-based ultra-high temperature ceramic welding joint and its preparation method

technical field

The invention relates to a high-temperature solder of a zirconium diboride-based ultra-high-temperature ceramic material and an application thereof, belonging to the technical field of ceramic material welding.

Background technique

Zirconium diboride (ZrB ₂ ), as a kind of Ultra High Temperature Ceramics (UHTCs) material, has high melting point, high strength, high modulus, high hardness, high thermal conductivity, high electrical conductivity and good oxidation resistance and Excellent comprehensive performance such as chemical corrosion resistance.

However, in practical applications, limited by the preparation process and equipment conditions, it is difficult to directly manufacture large-sized and complex-shaped ceramic components; also face enormous challenges. Ceramic welding is easy to solve this problem.

At present, in the research on welding of UHTCs materials, most of them use active metals (such as Ag, Cu, Au, Ni, Ti, Zr, Pd, etc.) or their alloy solders, and there are no reports on other high-temperature welding materials. However, active metals as solders mainly have the following problems: (1) Active solders usually have a low melting point, and the welding temperature is generally <1000 °C, and the high temperature resistance of welded ceramic joints is poor, which is contrary to the ultra-high temperature application background of UHTCs materials; (2) The huge difference between the thermal expansion coefficient of active solder (about 20ppm/K) and UHTCs material (<10ppm/K), resulting in a large residual thermal stress in the solder joint, affecting the reliability of the material, thus hindering UHTCs Wide application of welding materials.

Contents of the invention

The present invention aims to provide a high-temperature solder suitable for ZrB2 _- based UHTCs materials and its application, to solve the problems of low soldering temperature and low reliability of soldered joints existing in existing solders, and to provide _ZrB2 with large size and complex shape The preparation of UHTCs-based materials provides a method to reduce processing costs and improve production efficiency, thereby promoting the wide application of UHTCs materials.

First, the present invention provides a zirconium diboride-based ultra-high temperature ceramic welded joint, which is characterized in that the zirconium diboride-based ultra-high temperature ceramic welded joint includes at least two zirconium diboride-based ultra-high temperature ceramic substrates and The ultra-high temperature solder layer between the zirconium diboride-based ultra-high temperature ceramic substrate, wherein there is an interfacial reaction layer formed by mutual penetration between the zirconium diboride-based ultra-high temperature ceramic substrate and the high-temperature solder layer, so The chemical composition of the high-temperature solder layer is Ni _1-xy A _x B _y , wherein A is at least one of molybdenum and chromium, and B is at least one of tungsten, cobalt, iron, zirconium and titanium, 0<x≤ 0.6, 0≤y≤0.25.

In the zirconium diboride-based ultra-high temperature ceramic welding joint provided by the present invention, the solder layer is a nickel-based alloy, which can withstand high temperatures, and its expansion coefficient is ~10.6×10 ^-6 (1/K), which is comparable to that of zirconium diboride The base ultra-high temperature ceramics are close to each other, and the formed welding interface has good bonding and good stability, which is suitable for ultra-high temperature applications of UHTCs materials. Moreover, in the welded joint of the present invention, an interfacial reaction layer formed by the interpenetration of the two is also formed between the ultra-high temperature ceramic substrate and the solder layer. The elements in the interfacial reaction layer present a gradient distribution, and the degree of combination of the two is further enhanced. . And the test proves: the high-temperature solder provided by the present invention not only has good wettability, but also has similar thermophysical properties (good high-temperature thermodynamics, oxidation resistance and corrosion resistance) with the ZrB ₂ -SiC ceramic matrix, thereby reducing The influence of welded joints on the overall performance of UHTCs material welded parts is eliminated; at the same time, the reliability of ceramic welding materials is improved, which is conducive to the promotion of the application of ZrB ₂ -based UHTCs materials.

Preferably, the thickness of the ultra-high temperature solder layer is 10-1000 microns, preferably 50-200 microns.

Preferably, the thickness of the interface reaction layer is 100-500 microns.

In the present invention, the zirconium diboride-based ultra-high temperature ceramic matrix is a dense ZrB ₂ -SiC composite ceramic, wherein the mass percentage of ZrB ₂ is 50-100 wt%.

The present invention also provides a method for preparing the above-mentioned zirconium diboride-based ultra-high temperature ceramic welding joint, which includes: weighing each metal raw material according to the chemical composition of the high-temperature solder layer, adding a binder and a solvent, and mixing by ball milling to prepare a paste Shaped solder, wherein the mass ratio of the total mass of metal raw materials, binder and solvent is 100: (5-15): (65-150). Coating the paste solder on the surface to be welded of the zirconium diboride-based ultra-high temperature ceramic substrate that has been cleaned and pretreated to form a ceramic-solder layer-ceramic sandwich structure; and putting it into a high-temperature furnace for high-temperature welding .

Preferably, the powder of the metal raw material is a nanometer or submicron powder with a purity of more than 99%.

Preferably, the high temperature furnace can be a graphite carbon tube furnace.

Preferably, the process parameters of the high-temperature welding are: under vacuum or an inert atmosphere, first raise the temperature to a welding temperature of 1300°C-1700°C at a rate of 5-20°C/min, and keep it warm for 0.5-2 hours; Cool down to 300-700°C at a rate of 10°C/min; finally cool down to room temperature with the furnace.

Preferably, the binder is polyvinyl butyral or ethyl cellulose or the like.

Preferably, the solvent is absolute ethanol or a mixture of absolute ethanol and butanone (for example, the mass ratio is 4:6) and the like.

Description of drawings

Figure 1 is the curve of the contact angle of pure Ni and its alloys on ZrB ₂ -SiC ceramics as a function of temperature;

Fig. 2 is a photograph of the interface microstructure of the ZrB ₂ -SiC welded joint obtained in Example 1 of the present invention;

Fig. 3 is a photograph of the interface microstructure of the ZrB ₂ -SiC welded joint obtained in Example 2 of the present invention;

Fig. 4 is a photograph of the interface microstructure of the ZrB ₂ -SiC welded joint obtained in Example 3 of the present invention.

detailed description

The present invention will be further described below in conjunction with the drawings and the following embodiments. It should be understood that the drawings and the following embodiments are only used to illustrate the present invention rather than limit the present invention.

First, the preparation method of the ultra-high temperature welded joint of the present invention is exemplified.

The nickel-based alloy metal solder is prepared by selecting metal raw materials, and the metal raw materials can be selected from metallic nickel, metallic molybdenum and/or metallic chromium alloyed with metallic nickel. In addition, a small amount of tungsten (W), cobalt (Co), iron (Fe), zirconium (Zr), titanium (Ti) and the like can be added. The formula of each component in the metal raw material can be 5-30wt% Mo, 0-30wt.% Cr, 0-5wt.% W, 0-5wt.% Co, 0-5wt.% Fe, 0-5wt.% Zr , 0~5wt.% Ti, and the rest is Ni (40~75wt%). The powder of the metal raw material is preferably nanometer or submicron powder with a purity of more than 99%.

Add binder and solvent to metal raw materials, and ball mill to prepare paste slurry for high temperature welding. The binder can be polyvinyl butyral (PVB), but it should be understood that it is not limited thereto, for example, ethyl cellulose can also be used. The solvent can be absolute ethanol or a mixture of absolute ethanol and methyl ethyl ketone (mass ratio is 4:6), etc. The mass ratio of the total mass of the metal raw material, the binder and the solvent is 100:(5-15):(65-150).

The zirconium diboride-based ultra-high temperature ceramics are ready for use after the welding surface is polished, cleaned and dried. Grinding can be carried out with water sandpaper, and cleaning can be followed by ultrasonic cleaning in solvents such as acetone and alcohol. The zirconium diboride-based ultra-high temperature ceramics can be pure zirconium diboride ceramics, and the content of zirconium diboride is more than 50 wt%.

Apply creamy solder evenly on the surface to be soldered of ZrB ₂ -SiC ceramics to form a ceramic-solder-ceramic three-layer structure, which can be fixed with the aid of a clamp. Preferably, the thickness of the solder layer is 10-1000 microns, more preferably 50-200 microns.

Put the above-mentioned three-layer structure sample into a high-temperature furnace (such as a graphite carbon tube furnace) for high-temperature welding. For example, under an argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure, and the temperature is first raised to 1300-1700°C, keep warm for 0.5-2 hours, then cool down to 300-700°C at a rate of 3-10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints.

The photos of the microstructure of the formed welding joint are shown in Fig. 2 and Fig. 3. It can be seen that the bonding effect of the welded joint interface is good, and there is no lack of welding. Moreover, a reaction interface layer formed by mutual penetration between the ceramic substrate and the solder layer is formed, and the thickness of the interface layer is about 100-200 microns.

Tests have proved that the contact angle of the high-temperature solder provided by the present invention on the ZrB ₂ -SiC ceramic substrate is less than 20° at 1600°C (see Figure 1), has good wettability, and the nickel-based alloy solder is used as a Superalloy itself has good high-temperature thermodynamics, oxidation resistance and corrosion resistance, which are similar to the thermophysical properties of ZrB ₂ -SiC ceramic matrix, which can reduce the influence of welded joints on the overall performance of UHTCs material welded parts; at the same time improve ceramic welding The reliability of the material is conducive to the promotion of the application of ZrB ₂ -based UHTCs materials.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

1. Mix nano-scale Ni, Mo, Cr, and Fe powders according to the ratio of 67Ni-30Mo-1Cr-2Fe (that is, the mass percentages are 67%, 30%, 1%, and 2% respectively), and add the mass percentage 5wt% polyvinyl butyral (PVB) and 40wt% dehydrated alcohol by mass percent, ball milled the mixture in a planetary ball mill for 24 hours to obtain a uniform paste solder for subsequent use;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into the graphite carbon tube furnace. Under the argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1500°C at a rate of 5°C/min and kept for 1 hour. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The interface microstructure photos of the welded joints are shown in Fig. 2. It can be seen that the bonding effect of the welded joint interface is good, and there is no lack of welding.

Example 2

1. The powders of nanoscale Ni, Mo, Cr, W, Co, and Fe are mixed according to 57Ni-16Mo-16Cr-4W-2Co-5Fe (that is, the mass percentages are 57%, 16%, 16%, and 4% respectively. , 2%, 5%) were mixed in proportion, adding mass percent was 8wt% polyvinyl butyral (PVB) and mass percent was a mixture of absolute ethanol and methyl ethyl ketone (mass ratio was 4:6) , mill the mixture in a planetary ball mill for 24 hours to obtain a uniform creamy solder, and set aside;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into the graphite carbon tube furnace. Under the argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1450°C at a rate of 10°C/min, and the temperature is kept for 0.5 hours. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The photo of the interface microstructure of the welded joint is shown in Figure 3. It can be seen that the interface bonding effect of the welded joint is good, and there is no false welding phenomenon.

Example 3

1. The nano-scale Ni, Mo, Cr, W, Co, Fe powders are mixed according to 43Ni-14Mo-30Cr-3W-5Co-5Fe (that is, the mass percentages are 43%, 14%, 30%, 3% respectively , 5%, 5%) are mixed in proportion, adding mass percent is 10wt% polyvinyl butyral (PVB) and mass percent is the dehydrated alcohol of 50wt%, and ball milling mixes 24 hours in planetary ball mill, obtains Uniform paste solder, set aside;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into the graphite carbon tube furnace. Under the argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1450°C at a rate of 5°C/min and kept for 1 hour. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The microstructure photo of the interface of the welded joint is shown in Figure 4. It can be seen that the elements of the welded joint diffuse significantly and are evenly distributed, the interface is good, and there is no virtual welding phenomenon.

Example 4

1. Mix nano-scale Ni, Mo, Cr, and Fe powders according to the ratio of 75Ni-15Mo-6Cr-4Fe (that is, the mass percentages are 75%, 15%, 6%, and 4% respectively), and add the mass percentage 12wt% polyvinyl butyral (PVB) and 55wt% absolute ethanol by weight, ball-milled the mixture in a planetary ball mill for 24 hours to obtain a uniform creamy solder for subsequent use;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into a graphite carbon tube furnace. Under an argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1450°C at a rate of 5°C/min and kept for 2 hours. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The analysis shows that the elements of the formed welded joints have obvious diffusion and uniform distribution (similar to Figure 4), the interface bonding effect is good, and there is no false welding phenomenon.

Example 5

1. The powders of nano-scale Ni, Mo, Cr, Fe, Zr, according to 58Ni-8Mo-30Cr-2Fe-2Zr (that is, the mass percentages are 58%, 8%, 30%, 2%, 2%) The ratio of mixing, adding mass percent is 15wt% polyvinyl butyral (PVB) and mass percent is the dehydrated alcohol of 60wt%, in planetary ball mill ball mill mixing 24 hours, obtain uniform paste solder, standby ;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into a graphite carbon tube furnace. Under an argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1600°C at a rate of 5°C/min and kept for 1 hour. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The analysis shows that the interdiffusion of elements in the formed welded joint is obvious and evenly distributed (similar to Figure 4), and the interface bonding is good without virtual welding.

Example 6

1. Mix nano-scale Ni, Mo, Cr and Ti powders according to the ratio of 59Ni-16Mo-23Cr-2Ti (that is, the mass percentages are 59%, 16%, 23%, and 2% respectively), and add the mass percentage Be the mixture (mass ratio is 4:6) of the polyvinyl butyral (PVB) of 10wt% and the mass percent of 50wt% dehydrated alcohol and methyl ethyl ketone, ball milling mixes 24 hours in planetary ball mill, obtains uniform The paste solder, spare;

2. Polish the surface of the ZrB ₂ -SiC ceramic to be welded with No. 600 water sandpaper, then put it into acetone and alcohol for ultrasonic cleaning for 30 minutes, and dry it for later use;

3. Evenly coat the solder on the surface of the ZrB ₂ -SiC ceramic to be welded to form a ceramic-solder-ceramic three-layer structure, and fix it with a fixture. The thickness of the solder layer is 10-1000 microns;

4. Put the three-layer structure sample fixed by the above fixture into a graphite carbon tube furnace. Under an argon atmosphere, the pressure in the furnace is maintained at a standard atmospheric pressure. First, the temperature is raised to 1500°C at a rate of 5°C/min and kept for 2 hours. , then cool down to 500°C at 10°C/min, and then cool down to room temperature with the furnace to complete the welding of ZrB ₂ -SiC ceramic joints;

The analysis shows that the interdiffusion of elements in the formed welded joint is obvious and evenly distributed (similar to Figure 4), the interface bonding effect is good, and there is no virtual welding phenomenon.

Claims (10)

1. a kind of Zirconium Diboride-based Ultra-high Temperature Ceramics welding point, it is characterized in that, the Zirconium Diboride-based Ultra-high Temperature Ceramics welding point includes at least two Zirconium Diboride-based Ultra-high Temperature Ceramics matrixes and the superhigh temperature solder layer between the Zirconium Diboride-based Ultra-high Temperature Ceramics matrix, wherein there is the interfacial reaction layer for being interpenetrated by both and being formed between the Zirconium Diboride-based Ultra-high Temperature Ceramics matrix and high-temperature solder layer, the chemical composition of the high-temperature solder layer is Ni_1-x-yA_xB_y, wherein A is at least one in molybdenum, chromium, and B is at least one in tungsten, cobalt, iron, zirconium, titanium, 0<X≤0.6,0≤y≤0.25.

2. Zirconium Diboride-based Ultra-high Temperature Ceramics welding point according to claim 1, it is characterised in that the thickness of the superhigh temperature solder layer is 10~1000 microns, preferably 50~200 microns.

3. Zirconium Diboride-based Ultra-high Temperature Ceramics welding point according to claim 2, it is characterised in that the thickness of the interfacial reaction layer is 100~500 microns.

4. Zirconium Diboride-based Ultra-high Temperature Ceramics welding point according to any one of claim 1 to 3, it is characterised in that the Zirconium Diboride-based Ultra-high Temperature Ceramics matrix is fine and close ZrB₂- SiC composite ceramicses, wherein ZrB₂The mass percent for accounting for is 50~100wt%.

5. a kind of method of the Zirconium Diboride-based Ultra-high Temperature Ceramics welding point prepared any one of Claims 1-4, it is characterised in that including：Chemical composition according to high-temperature solder layer weighs each raw metal, adds binding agent and solvent, and ball milling mixing is obtained cream solder, and the wherein mass ratio of the gross mass of raw metal, binding agent and solvent is 100：（5~15）：（65~150）；The cream solder is coated on the surface to be welded of the Zirconium Diboride-based Ultra-high Temperature Ceramics matrix pre-processed through surface cleaning, makes to form ceramics-solder layer-ceramics sandwich structure；And be put into high temperature furnace and carry out high-temperature soldering.

6. method according to claim 5, it is characterised in that the powder of the raw metal is nanometer or submicron powder, and purity is more than 99%.

7. the method according to claim 5 or 6, it is characterised in that the high temperature furnace is graphite carbon shirt-circuiting furnace.

8. the method according to any one of claim 5 to 7, it is characterised in that the technological parameter of the high-temperature soldering is：Under vacuum or inert atmosphere, 1300 DEG C ~ 1700 DEG C of welding temperature is first warmed up to 5 ~ 20 DEG C/min of speed, is incubated 0.5 ~ 2 hour；Then 300~700 DEG C are cooled to 3 ~ 10 DEG C/min of speed；Finally room temperature is cooled to stove.

9. the method according to any one of claim 5 to 8, it is characterised in that the binding agent is polyvinyl butyral resin or ethyl cellulose type.

10. the method according to any one of claim 5 to 9, it is characterised in that the solvent is the mixture of absolute ethyl alcohol or absolute ethyl alcohol and butanone.