Production of iron matrix composite reinforced by TiN particulate through nitriding by powder metallurgy

摘要

An iron matrix composite reinforced by TiN particulate is fabricated by nitriding and by powder metallurgy. The results show that chromium nitrides and titanium nitride can be in situ synthesised in the prealloyed powder when nitriding at 1100-1250 deg C in pure nitrogen atmosphere. After the denitrification at 1300 deg C in vacuum below 10~(-2) Pa, the chromium nitrides decompose, but titanium nitride still exists stably. The titanium nitride particulates have fine size and are homogeneously distributed in the matrix. The relative density of the sintered compact is approx 99 percent by spark plasma sintering at 1000 deg C and 40 MPa. However, it is very low (approx 90 percent) when the denitrified powder is sintered at 1400 deg C in vacuum.