PROPERTIES OF ALUMINUM BASED COMPOSITE IN DIFFERENT QUENCHING MEDIA

Particle reinforced aluminum matrix composites are frequently used in various automotive and aerospace applications involving critical functions like piston rings, wing mid and inner cover etc. Here, the composites are frequently subjected to extreme conditions involving large temperature differentials in a short period of time which can damage the particle matrix interface resulting in a decreased ability to resist matrix deformation or strengthen the matrix through dislocation generation from the thermal misfit between matrix and reinforcement. Hence, this phenomenon has been investigated in the course of this work by quenching aluminum-alumina micro and nano composites in different quenchants and studying the effects on mechanical properties as well as microstructure. Increase in hardness was likely due to dislocation generation as was realized from the greater increase for higher vol. fraction reinforcement composites, while post quench softening was likely due to decohesion and cracking of particles and interfacial damage.