Effect of Cooling Rate Applied to Aluminum Composites on Hardness and Wear Resistance

Cooling process applied to complete sintering cycle of aluminum composites produced by hot pressing method has a great effect on grain size, hardness and wear resistance. In order to obtain a fine-grained microstructure, increase hardness and reduce amount of wear, cooling process of the composites was carried out in two stages. First of these is 12 m3/minute cold air flow blowing on punch connected to mold during time composites descended to semi-liquid/semi-solid temperature and second is 0.35 L/min constant water flow given to bottom mold after composites are removed from furnace. After increasing cooling rate in this way, it was observed to rise that the hardness and wear resistance to a half fold.