Sintering of Nickel-Bonded Titanium Carbides
1964 年 5 巻 1 号 p. 1-7
詳細
1964 年 5 巻 1 号 p. 1-7
An experimental investigation of the sintering process of nickel-bonded titanium carbides was carried out by means of dilatometric and metallographic methods. Linear shrinkage of compacts of mixed powders of nickel and titanium carbide of various compositions (0, 10, 20, 30, 40, 50 and 75% nickel in the weight ratio) was measured during sintering with a silicon carbide dilatometer. The temperature was raised at the rate of 250°C/hr up to 1500°C and kept constant for 1 hr and then lowered at the same rate. In most cases, except for 0% and 75% nickel, linear shrinkage of the compacts was very slight up to about 1200°C, but the abrupt shrinkage corresponding to the appearance of a liquid phase was observed over the temperature range of 1200∼1350°C. The total shrinkage during sintering increased, while the starting temperature of the abrupt shrinkage decreased with the increase in nickel content. The linear shrinkage at the temperature of 1500°C was proportional to logarithm of sintering time. It was shown by the metallographic examination that the shape of carbide grains changed from round to angular with the increase in nickel content. The grain size and the sphericity index of titanium carbide, however, did not change so much with the nickel content under the same sintering conditions. The change in the shape of carbide grains may be attributed to the continuity of a binder phase in compact.
