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| Shape: | Block, Powder |
| Purification Method: | Zone Refining |
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Product name: 10 cobalt tungsten carbide powder, 10 nickel tungsten carbide powder, 10 cobalt 4 chromium tungsten carbide powder
Ingredient content: Co:10%,WC allowance; Co10%, Cr4%, WC allowance; Ni:10%, WC allowance
Size: 100-325 mesh
Application Field:
Hard alloy, metal surface treatment.
Cobalt - based tungsten carbonized alloy powder HVOF spraying
In tungsten carbide, carbon atoms are inserted into the gaps of the tungsten metal lattice without destroying the original metal lattice, forming interstitial solid solutions, so it is also called interstitial (or interstitial) compounds. Tungsten carbide can be prepared by heating a mixture of tungsten and carbon at high temperatures. The presence of hydrogen or hydrocarbons accelerates the reaction. If tungsten containing oxygen is used for preparation, the product must eventually be vacuum treated at 1500ºC to remove the carbon and oxygen compounds. Tungsten carbide is suitable for mechanical processing at high temperatures, and can be used to make cutting tools, structural materials for kilns, jet engines, gas turbines, nozzles, etc.
Another compound of tungsten and carbon is ditungsten carbide, chemical formula W2C, melting point 2860ºC, boiling point 6000ºC, relative density 17.15. Its property, process and use are the same as tungsten carbide.
Using HVOF spraying cobalt based tungsten carbide alloy powder or nickel based tungsten carbide alloy powder and chromium based tungsten carbide alloy powder hardness can reach HV1200 high temperature resistance 850 degrees, so that the valve parts, wear resistance, corrosion resistance, high temperature resistance, oxidation resistance. It is more than manual surfacing welding, chrome crossing, carburizing, tempering and processing, which can increase the production efficiency by more than 2 times, reduce the production cost by more than 50%, and extend the service life by dozens of times.
The invention relates to a tungsten carbide reinforced cobalt matrix composite material used for plasma cladding of copper matrix. With copper as the base layer, a nickel layer is plated on the surface of copper to improve the morphology of the cladding coating and reduce the influence of copper oxide. The composite powder of stellite6 alloy and tungsten carbide is uniformly mixed as the powder used for plasma cladding, and plasma melting is performed on the surface of copper
To obtain a tungsten carbide reinforced cobalt alloy composite coating whose strength, hardness, wear resistance, melting point and other important properties are much higher than copper. In order to stabilize the morphology of the cladding layer, make the cladding layer and copper matrix can be closely combined, and reduce the generation of pores, it is necessary to strictly control the parameters of the whole process. In order to reduce the influence of copper oxide on coating quality during the cladding process, such as porosity, reduction and polarization of copper oxide, wetting Angle, a nickel layer was electroplated on the surface of copper matrix. Due to the direct air cooling after cladding, the phase of the cladding coating is in an unstable state, with uneven distribution of all phases and inadequate reaction. Therefore, the cladding coating is treated at high temperature for a long time to transform the phase into a stable state and improve the performance of the cladding coating. Gradient plasma cladding coating makes the coating have good hardness and wear resistance, and can effectively control the number of macroscopic defects.
7. To realize the above purpose, the invention provides a tungsten carbide reinforced cobalt matrix composite material for plasma cladding of copper matrix in the first aspect, which is characterized in that it comprises a cobalt alloy matrix and a tungsten carbide ceramic reinforced phase, in which the proportion of tungsten carbide is 30%
40wt %.
8. Further, stellite6 cobalt-based alloy with the morphology of particle size of 45μm was used
55μm spherical powder.
9. Further, the morphology of tungsten carbide particle size is 45μm
55μm spherical powder.
10. In the second aspect, the invention provides a method of applying tungsten carbide reinforced cobalt matrix composite material to copper matrix plasma cladding, which is characterized in the following steps:
11.(1) Cobalt-based alloy was used as the matrix cladding material. The morphology of cobalt-based alloy was 45μm in particle size
55μm spherical powder; Tungsten carbide was used as the ceramic strengthening phase, in which the morphology of tungsten carbide particle size was 45μm
55μm spherical powder;
12.(2) Press the spherical powder of cobalt-based alloy and tungsten carbide by 30%
The mixture was weighed at a ratio of 40wt %, mixed evenly with a powder mixing device and then placed in the oven for drying for 120 minutes;
13.(3) Plating nickel layer on the surface of copper matrix to cover the surface of copper matrix;
14.(4) Load the mixed powder into the powder feeder of the plasma surfacing equipment and preheat the copper matrix to 800ºC for cladding. The cladding parameters are as follows: The speed is set at 180mm/s, the powder delivery quantity is set at 30g/min, the ion gas flow rate is set at 3l/min, the protection gas flow rate is set at 12l/min, the powder delivery gas flow rate is set at 3l/min, and the current is set at 140a. Plasma cladding coating was obtained after cooling in air.
15.(5) The plasma cladding coating is aged for 240h to transform the non-stable phase of the plasma cladding coating into a stable state.
16. Further, stellite6 cobalt-based alloy is used.
17. Further, three kinds of mixed powders with spherical powder mixing ratios of cobalt base alloy and tungsten carbide of 20%, 30% and 40% were prepared respectively, and step (4) was repeated to form three gradient plasma cladding coatings on the copper matrix successively.
18. Further, the plasma cladding coating is aged for 240h to transform the non-stable phase of the plasma cladding coating into a stable state.
19. According to the theoretical data support, the invention selects stellite6 cobalt-based alloy powder and spherical tungsten carbide powder which have been used in the industry as raw materials; The wettability of cobalt-based cladding coating was improved by electroplating nickel layer on the surface of copper matrix and porosity was reduced. The influence of addition of tungsten carbide on many physical properties of cladding coating was summarized by control experiments with control variables, and the most appropriate proportion of addition of tungsten carbide was evaluated. The aim is to prepare the plasma cladding protective coating to improve the surface of copper by the optimal ratio of control experiment. The composite coating was homogenized by long time high temperature aging treatment and the final quality of the coating was improved. The purpose is to prepare composite coatings on the surface of copper with higher hardness and wear resistance than copper and copper alloy, and improve the hardness and wear resistance of copper and copper alloy workpiece. Gradient plasma cladding coating makes the coating have good hardness and wear resistance, and can effectively control the number of macroscopic defects.
20. The conception of the invention, the specific structure and the resulting technical effect are further explained in combination with the attached drawings in order to
Fully understand the purpose, features and effects of the invention.
Attached drawing description
21. FIG. 1 shows the curve of the friction coefficient with time for the sample without adding tungsten carbide, the sample with 20% tungsten carbide ratio and the sample with 40% tungsten carbide ratio;
22. Figure 2 shows the hardness curve of each sample as the distance from the top of the cladding layer changes;
23. FIG. 3 shows an electron microscope image of the cladding coating with 40% tungsten carbide ratio without aging treatment;
24. Figure 4 shows the electron microscope image of the cladding coating with 40% tungsten carbide ratio after being aged at 500ºC for 240h.
Specific mode of implementation
25. A number of preferred embodiments of the invention are described in the drawings attached to the reference specification below to make the technical content clearer and easier to understand. The invention may be embodied by a number of embodiments in different forms and the scope of protection of the invention is not limited to the embodiments mentioned herein.
26. The present invention is described in detail by specific embodiments.
27. Example 1
28.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with a particle size of about 50μm; Tungsten carbide was used as the ceramic strengthening phase, and the morphology was also about 50μm spherical powder.
29.(II) Weigh 180g of stellite6 cobalt-based alloy powder and 20g of tungsten carbide powder, put them into the powder mixing device, and add anhydrous ethanol for wet mixing for 24 hours.After being evenly mixed together, remove the anhydrous ethanol and place it in the oven for drying for 120 minutes. Filter the powder less than 100 mesh and more than 300 mesh with a 100 mesh and 300 mesh sieve, and put it into the mortar for full grinding. Then collect the powder and keep it sealed in the dehumidifier cabinet.
30.(3) Load the mixed powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feed amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feed gas = 3l/min, current = 140a. The copper substrate with nickel coating was preheated to 800ºC by induction current, and then the plasma cladding coating was obtained after cooling in air.
31.(IV) Cut the copper block with plasma cladding coating into small pieces with a wire cutter, and dot the cross section of the cladding coating with a microhardness tester; The remaining parts were cut into cylinders, and the friction coefficient and friction weight loss of the samples were measured by the tribometer. The influence of the addition of 10% tungsten carbide on the hardness and wear resistance of stellite6 cobalt-based alloy was analyzed.
32. Embodiment 2
33.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with a particle size of about 50μm; Tungsten carbide was used as the ceramic strengthening phase, and the morphology was also about 50μm spherical powder.
34.(II) Weigh 160g of stellite6 cobalt-based alloy powder and 40g of tungsten carbide powder, put them into the powder mixing device, and add anhydrous ethanol for wet mixing for 24 hours.After being evenly mixed together, remove the anhydrous ethanol and place it in the oven for drying for 120 minutes. Filter the powder less than 100 mesh and more than 300 mesh with a 100 mesh and 300 mesh sieve, and put it into the mortar for full grinding. Then collect the powder and keep it sealed in the dehumidifier cabinet.
35.(3) Load the mixed powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feed amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feed gas = 3l/min, current = 140a. The copper matrix with nickel coating was preheated to 800ºC by induction current and then cladding was made after cooling in air
To plasma cladding coating.
36.(IV) Cut the copper block with plasma cladding coating into small pieces with a wire cutter, and dot the cross section of the cladding coating with a microhardness tester; The remaining parts were cut into cylinders, and the friction coefficient and friction weight loss of the samples were tested by tribometer. The influence of the addition of 20% tungsten carbide on the hardness and wear resistance of stellite6 cobalt-based alloy was analyzed.
37. Example 3
38.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with a particle size of about 50μm; Tungsten carbide was used as the ceramic strengthening phase, and the morphology was also about 50μm spherical powder.
39.(II) Weigh 140g of stellite6 cobalt-based alloy powder and 60g of tungsten carbide powder, put them into the powder mixing device, and add anhydrous ethanol for wet mixing for 24 hours.After being evenly mixed together, remove the anhydrous ethanol and place it in the oven for drying for 120 minutes. Filter the powder less than 100 mesh and more than 300 mesh with a 100 mesh and 300 mesh sieve, and put it into the mortar for full grinding. Then collect the powder and keep it sealed in the dehumidifier cabinet.
40.(III) Load the mixed powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feed amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feed gas = 3l/min, current = 140a. The copper substrate with nickel coating was preheated to 800ºC by induction current, and then the plasma cladding coating was obtained after cooling in air.
41.(IV) Cut the copper block with plasma cladding coating into small pieces with a wire cutter, and dot the cross section of the cladding coating with a microhardness tester; The remaining parts were cut into cylinders, and the friction coefficient and friction weight loss of the samples were tested by tribometer. The influence of the addition of 30% tungsten carbide on the hardness and wear resistance of stellite6 cobalt-based alloy was analyzed.
42. Example 4
43.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with a particle size of about 50μm; Tungsten carbide was used as the ceramic strengthening phase, and the morphology was also about 50μm spherical powder.
44.(II) Weigh 120g of stellite6 cobalt-based alloy powder and 80g of tungsten carbide powder, put them into the powder mixing device, and add anhydrous ethanol for wet mixing for 24 hours.After being evenly mixed together, remove the anhydrous ethanol and place it in the oven for drying for 120 minutes. Filter the powder less than 100 mesh and more than 300 mesh with a 100 mesh and 300 mesh sieve, and put it into the mortar for full grinding. Then collect the powder and keep it sealed in the dehumidifier cabinet.
45.(3) Load the mixed powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feed amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feed gas = 3l/min, current = 140a. The copper substrate with nickel coating was preheated to 800ºC by induction current, and then the plasma cladding coating was obtained after cooling in air.
46.(IV) Cut the copper block with plasma cladding coating into small pieces with a wire cutter, and dot the cross section of the cladding coating with a microhardness tester; The remaining parts were cut into cylinders, and the friction coefficient and friction weight loss of the samples were tested by tribometer. The influence of addition of 40% tungsten carbide on the hardness and wear resistance of stellite6 cobalt-based alloy was analyzed.
47. Example 5
48.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with particle size of about 50μm;
49.(ii) Weigh 200g of stellite6 cobalt-based alloy powder, filter out the powder smaller than 100 mesh and larger than 300 mesh with a 100-mesh and 300-mesh sieve, put it into a mortar and fully grind it, then collect the powder and store it sealed in a dehumidifier.
50.(4) Load the powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feeding amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feeding gas = 3l/min, current =
140 a. The copper substrate with nickel coating was preheated to 800ºC by induction current, and then the plasma cladding coating was obtained after cooling in air.
51.(v) Cut the copper block with plasma cladding coating into small pieces with a wire cutter, and dot the cross section of the cladding coating with a microhardness tester; The remaining part was cut into a cylinder, and the friction coefficient and friction weight loss of the sample were measured by the tribometer, and the hardness and wear resistance of stellite6 cobalt-based alloy were analyzed.
52. Experimental example 6
53.(I) stellite6 cobalt-based alloy is selected as the matrix cladding material. The morphology of cobalt-based alloy is spherical powder with a particle size of about 50μm; Tungsten carbide was used as the ceramic strengthening phase, and the morphology was also about 50μm spherical powder.
54.(II) Weigh 120g of stellite6 cobalt-based alloy powder and 80g of tungsten carbide powder, put them into the powder mixing device, and add anhydrous ethanol for wet mixing for 24 hours.After being evenly mixed together, remove the anhydrous ethanol and place it in the oven for drying for 120 minutes. Filter the powder less than 100 mesh and more than 300 mesh with a 100 mesh and 300 mesh sieve, and put it into the mortar for full grinding. Then collect the powder and keep it sealed in the dehumidifier cabinet.
55.(III) Load the mixed powder into bx
zd
In the powder feeder of 400b plasma surfacing equipment, the cladding parameters are as follows: speed = 180mm/s, powder feed amount = 30g/min, ionic gas = 3l/min, protective gas = 12l/min, powder feed gas = 3l/min, current = 140a. The copper substrate with nickel coating was preheated to 800ºC by induction current, and then the plasma cladding coating was obtained after cooling in air.
56.(4) Place the copper block with plasma cladding coating in a tubular furnace and keep it warm for 240h at 500ºC in an air atmosphere.
57.(v) The copper block with plasma cladding coating is cut into small pieces with a wire cutter. The cross section of the cladding coating is dotted with a microhardness tester and scanned by sem to observe the phase changes after a long time of high temperature aging; The remaining part was cut into a cylinder, and the friction coefficient and friction weight loss of the sample were measured by the tribometer, and the change of friction resistance after a long time of high temperature aging at 500ºC was analyzed.
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