The invention provides a method for preparing tungsten disilicide powder, which comprises the following steps: mixing tungsten powder and silicon powder in a ratio of 1 ∶ 2, mixing titanium powder and graphite powder in a ratio of 1 ∶ 1, and then mixing them evenly; Put the W-Si mixed powder in the center of the crucible, and put the Ti-C mixed powder evenly between the W-Si mixed powder and the crucible. Finally, put a layer of Ti-C mixed powder on the top of all the mixed powder. The weight ratio of the Ti-C mixed powder and the W-Si mixed powder in the crucible is (0.8 ～ 1.2) ∶ 1; Put the crucible containing mixed powder into a closed reactor, vacuum it, fill it with argon, and then electrify it with tungsten wire to initiate the reaction between mixtures; After cooling, the reacted materials are taken out, titanium carbide and tungsten disilicide are separated, and titanium carbide and tungsten disilicide powder are obtained after crushing respectively. The invention has the advantages of simple process, energy saving and time saving. And TiC powder can be synthesized at the same time.
The specific preparation steps are as follows:
a. The tungsten powder and silicon powder are massaged at a ratio of 1 ∶ 2 for ingredients, the titanium powder and graphite powder are massaged at a ratio of 1 ∶ 1 for ingredients, and then mixed evenly;
b. Put the W-Si mixed powder in the center of the crucible, and put the Ti-C mixed powder evenly between the W-Si mixed powder and the crucible. Finally, put a layer of Ti-C mixed powder on the top of all the mixed powder. The weight ratio of the Ti-C mixed powder and the W-Si mixed powder in the crucible is (0.8~1.2) ∶ 1;
c. Put the crucible containing mixed powder into a closed reactor, vacuum it, fill it with argon, and then electrify it with tungsten wire to initiate the reaction between mixtures;
d. After cooling, take out the reacted materials, separate tungsten disilicide and titanium carbide, and obtain tungsten disilicide powder and titanium carbide powder after crushing.
The purpose of the invention is to provide a method for preparing tungsten disilicide powder, in which the reaction heat of a high exothermic system is used to heat and ignite the synthesis reaction of tungsten and silicon.
The preparation method of WSi2 of the invention comprises the following steps:
(1) The tungsten powder and silicon powder are massaged at a ratio of 1 ∶ 2 for ingredients, the titanium powder and graphite powder are massaged at a ratio of 1 ∶ 1 for ingredients, and then mixed evenly;
(2) Put the W-Si mixed powder in the center of the crucible, and put the Ti-C mixed powder evenly between the W-Si mixed powder and the crucible. Finally, put a layer of T i - C mixed powder on the top of all the mixed powder. The weight ratio of the Ti-C mixed powder and the W-Si mixed powder in the crucible is (0.8~1.2) ∶ 1;
(3) Put the crucible containing mixed powder into a closed reactor, vacuum it, fill it with argon, and then electrify it with tungsten wire to initiate the reaction between mixtures;
(4) After cooling, the reacted materials are taken out, titanium carbide and tungsten disilicide are separated, and titanium carbide and tungsten disilicide powder are obtained after crushing respectively. The combustion synthesis of titanium carbide from titanium and graphite is a highly exothermic reaction, and the adiabatic combustion temperature of the reaction T i+C → T i C is as high as 3210 K. The invention uses the reaction heat of this reaction to heat and ignite the reaction of synthesizing WSi2: W+2Si → WSi2.
The invention has the advantages of simple process, energy saving and time saving And TiC powder can be synthesized at the same time.
Description of attached drawings:
Figure 1 is the schematic diagram of the filling method of the mixed powder of titanium and graphite and the mixed powder of tungsten and silicon in the crucible of the invention. Tungsten wire 1, T i - C mixed powder 2, W - S i mixed powder 3 and crucible 4 used for ignition reaction in the figure. Figure 2 shows the X-ray diffraction pattern of the synthesized WSi 2 according to the invention. It can be seen that according to the invention
Get WSi2.
Specific embodiments:
Example 1: First, mix titanium powder, graphite powder, tungsten powder and silicon powder at a ratio of 1 ∶ 1 and 1 ∶ 2 respectively, and then put them into the crucible. The weight ratio of T i - C mixed powder and W - S i mixed powder filled in the crucible is 0.8:1, and the W - S i mixed powder is placed in the center of the crucible, T i - C mixed powder is evenly placed between the W - S i mixed powder and the crucible, and finally a layer of T i - C mixed powder is placed on the top of all mixed powders. After energizing the tungsten wire, ignite the Ti-C mixed powder on the top layer of the crucible.
Example 2: First, mix titanium powder, graphite powder, tungsten powder and silicon powder at a ratio of 1 ∶ 1 and 1 ∶ 2 respectively, and then put them into the crucible. The weight ratio of T i - C mixed powder and W - S i mixed powder filled in the crucible is 1.2:1, and the W - S i mixed powder is placed in the center of the crucible, T i - C mixed powder is evenly placed between the W - S i mixed powder and the crucible, and finally a layer of T i - C mixed powder is placed on the top of all mixed powders. With the downward spread of the T i - C reaction, its reaction heat heats and ignites the W - Si mixed powder. In this way, all mixed powders can fully react. While obtaining WSi2 powder, TiC powder can also be obtained.
