Dilatometric analysis of sintering of iron–boron–cobalt P/M metal matrix composites

The advantages of powder metallurgy technique may be used to produce novel composite materials with enhanced wear resistance. There are boride-based cermets among these materials. Therefore, the mechanism of liquid phase sintering of Astaloy Mo Höganäs grade powder with 9 wt.% of boron and 10 wt.% of cobalt additions was investigated. Since the elemental boron powder was used, the formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Thus dilatometry, as a most suitable method in such a case was chosen to control basic phenomena taking place during reactive sintering of investigated systems. The influence of heating rate and isothermal sintering temperature on dimensional changes was also investigated. The microstructure and phase constituents of sintered compacts were controlled as well.