Preparation and characteristics of Metal-Car- bide Composite Materials Using Plasma Powder Melting Method

Generally, particle composite alloy is fabricated by powder metallurgy. The other hand, Plasma Powder Melting (PPM) method has been put into practical use for welding machine in the field of surface hardening. In this study, it is attempted to fabricate metal-carbide composite materials using PPM method. Each metal (Fe, Ni, Co alloy) and carbide (Cr₃C₂, NbC, WC) powders are mixed, which are directly melted by plasma arc in the graphite mold so as to obtain metal-carbaide composite materials. In Fe-Cr₃C₂, Ni-Cr₃C₂, Fe-NbC, and Ni-NbC systems, the strength value of these composites were remarkably high in comparison with the products without reinforcing. The factor of strength is caused by change of matrix structure, dispersion of particles and residual stress between metal matrix and carbide. In all of the composites, bending modulus decreased monotonously with increasing of carbide, and hardness of these increased monotonously. It has succeeded in making 3-dimensional model of metal-carbide composites using PPM method.