Microstructure and mechanical properties of Al/(Ti,W)C composites prepared by microwave sintering

(Ti,W)C particulate reinforced 6061 Al alloy composites were prepared by microwave sintering method in this investigation. Green compacts containing different content of reinforcements (i.e., 10, 20 and 30 wt.% (Ti,W)C) were prepared and then sintered by microwave heating at four temperatures (i.e., 500 degrees C, 520 degrees C, 540 degrees C, 560 degrees C) with a constant soaking time of 45 min. The porosity was increased with an increase in the additive amount of (Ti,W)C particulates, firstly increased and then decreased with an increase in sintering temperature. The microstructure was characterized by uniform distribution of (Ti,W)C particulates in the Al alloy matrix. Grain size growth trend was readily controlled and small grain size was obtained even at higher sintering temperature owing to the addition of (Ti,W)C phase. Mechanical tests indicated that the average hardness, compressive yield strength as well as compression strength were enhanced with an increase in both (Ti,W)C particulate amount and sintering temperature (range from 520 degrees C to 560 degrees C). The interfacial structures between Al/(Ti,W)C, Al/ Al and (Ti,W)C/(Ti,W)C were revealed by TEM to investigate bounding mechanism during microwave sintering process. (C) 2013 Elsevier B.V. All rights reserved.