REGARDING THE NEAR NET SHAPE SYNTHESIS OF AN ANTIFRICTION COMPOSITE WITH IMPROVED MICROSTRUCTURE AND YIELD STRENGTH

In the present study, an aluminum-based metallic matrix (A1-4.5 wt% Cu ) was reinforced with graphite particulates, using the disintegrated m elt deposition technique. Microstructural characterization studies con ducted on the as-processed composite samples revealed the presence of significantly refined grain size (0.21 times of that exhibited by unre inforced samples) and an increasingly equiaxed grain morphology, compa red with the typical columnar/equiaxed grain morphology exhibited by t he unreinforced samples. In addition, the studies revealed the presenc e of minimal porosity (<1%), a mostly uniform distribution of graphite particulates, and a good graphite-matrix interfacial integrity. Resul ts of ambient-temperature tensile tests revealed that the presence of 5.1 wt% of graphite particulates led to similar to 52% increase in yie ld strength, while the ultimate tensile strength and ductility remaine d lower, compared with the unreinforced samples. An attempt is made to correlate the presence of graphite articulates with the microstructur e and mechanical properties variation exhibited by the A1-4.5 wt% Cu m atrix. (C) 1998 Elsevier Science Ltd.