Porous titanium-niobium alloy and preparation method thereof. The porous titanium-niobium alloy of the invention, according to the weight percentage, is divided into Nb35%, the remainder is Ti.
The preparation method of porous titanium-niobium alloy is as follows:
(1) The purity of titanium and niobium is 99.9%, and the particle size of Ti and Nb is 45 mesh and 325, respectively.
Spherical urea is used as blowing agent, the particle size is 200 ~ 500μm;
(2) According to mass percentage, 65% Ti powder and 35%Nb powder are weighed;
(3) The weighed raw material powder into the ball mill tank, filled with argon gas protection, and then mixed in the ball mill.
Uniform, ball grinding time is 40 minutes, speed is 110r/min, ball material ratio is 10:1;
(4) After the powder is mixed, when the temperature of the ball mill tank is close to room temperature, take out the powder and put it into a container
In addition, the weight of Ti, Nb powder 25%~62.5% of the weight of urea, mixed evenly;
(5) Pour the mixture powder of step (4) into the mold with a press at a pressure of 200MPa
Press and hold for 5 minutes;
(6) Take out the pressed sample, put it in the oven at 170oC for 2 hours, let the urea volatilize
Then it is put into the vacuum sintering furnace, the vacuum furnace vacuum to 10-5 ~ 10-6Torr, and then heated to 1200oC to hold the heat for 6 hours for sintering, cooling to room temperature can be taken out, the porous titanium niobium alloy, the aperture is 200 ~ 500μm, the porosity of 50 ~ 70%.
The invention has the advantages that the blowing agent urea used in the porous titanium-niobium alloy prepared by the powder metallurgy method of the invention can volatilize at a relatively low temperature, is easy to remove, and can control the shape, size, porosity and the uniformity of pore distribution within a certain range by adjusting the shape, size and amount of urea. For titanium-niobium alloys with high sintering temperature and easy oxidation, porous titanium-niobium alloys with good sintered quality can be obtained by high vacuum sintering under the condition of pre-formation of holes (compact without support body).
