Preparation methods of particle reinforced surface metal matrix composites

Preparation methods of particle reinforced surface metal matrix composites were classified according to the thermal sources used and the feeding of reinforcing ceramic particles.Hardfacing, laser cladding, laser melt injection and plasma melt injection were introduced, and the virtues and defects of all the methods were discussed.Metallurgical bonding between the substrate and the coating could be achieved with hardfacing, and it was very effective. Energy input could be controlled precisely in laser cladding process, and the cooling rate was high, so the thermal distortion was very little.While, cracks always appeared in the hardfacing and laser cladding process.Laser melt injection was not restricted by the weldability of the substrate, and coatings with uniformly distributed strengthening phases could be achieved with it, so cracks could be avoided in the laser melt injection process.The plasma melt injection process was similar to the laser melt injection process, and gradient composites with strengthening phases varying from 0 to 100% could be achieved with it.Cracks caused by unevenly distributed strengthening phases could be avoided.The investment for the plasma melt injection process was very low, and it was cost effective.