Ti(C,N)-Cr₃C₂混合粉の真空焼結

抄録

Ti(C, N), TiC, and TiN have high melting points, high hardness and extremely good wear resistance to steel. Among them, the densification of Ti(C, N) is easiest. However, the sintered body of pure Ti(C, N) has a porosity of several volume persent. The properties of Ti(C, N)-Cr₃C₂ ceramics were studied. Also, the densification behavior of the Ti(C, N)-Cr₃C₂ system was compared with those of the TiC-Cr₃C₂, TiN-Cr₃C₂ and TiC-TiN-Cr₃C₂ systems. The main results are as follows:
(1) The Ti(C, N)-Cr₃C₂ system can be sintered at relatively low temperatures from 1873 to 1973K The Cr₃C₂ additive plays an effective role in the densification of Ti(C, N).
(2) Ti(C, N)-5%Cr₃C₂ ceramics had a porosity of 0.1vol%, a transverse rupture strength of 450MPa and a Vickers hardness of 1900.
(3) In the TiC-20%Cr₃C₂ and TiN-20%Cr₃C₂ system, the chromium carbide phase dissolves completely into TiC and TiN, and does not remain among the grains. Thus, TiC and TiN grains grow.
(4) Both Ti(C, N)-20%Cr₃C₂ and TiC-TiN-20%Cr₃C₂ ceramics had a Cr₇C₃ phase among the grains. Cr₇C₃ restrains the Ti(C, N) grain growth more effectively than TiC-TiN grain growth.