Microstructure and abrasion resistance of tool steels reinforced by dispersed oxides and carbides phases

Two ferrous matrix, a high speed steel and a maraging steel were reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy. The particles were mechanically mixed with the prealloyed powder before compaction. To optimize the composite properties, the processing parameters (i.e. prealloyed powders, size, mixing, conditions, temperature of sintering,...) and the effect of reinforcement (size and composition of particles, volume, fraction,...) were studied. It is necessary to obtain full density with minimum porosity and to control the size, distribution and dispersion of the reinforced particles. The optimal sintering temperature depends on the reinforcement particles used and is of great importance for the properties. Processing parameters (mixing of particles) can greatly affect the final properties. The use of AL2O3 was shown to increases wear resistance in the two matrix.