Microstructure and densification behavior of liquid phase sintered Fe-Cu alloy powder using cold and hot compaction techniques

Abstract

The physical and mechanical properties of atomized prealloyed Fe-Cu powders, blended with different amounts of liquid additions of lead (Pb), were studied in the as-sintered condition and hot compaction techniques. The influence of Pb content, compacting pressure and temperature on the densification, hardness, and the mechanical properties were investigated. During hot compaction, at a temperature of 500 ° C, the Pb liquid was found to spread uniformly among Fe-Cu solid particles. The effect of pores in Fe-Cu-Pb alloys, generated by sintering with transient liquid phase, had been studied. An attempt was made in order to study the properties of Fe-Cu-Pb particles and their behaviour, with respect to the consolidation of Fe-Cu-Pb powders. The density values of cold and hot compacts, at various pressures and temperatures values, were reported. The microstructure, hardness, and strength measurements were found to be dependent upon the compacting pressure. For the cold compacted alloys, the Pb powder particles were completely melted to form liquid pools. In addition, increasing the Pb content in the alloy matrix revealed a decrease of the pores percentage, hence the sample became denser. On the other hand, grain was found to be coarser and less porosity is obtained with increasing the Pb content in the hot compacted. It is found that, increasing the compacting pressure of the cold and hot compacted samples revealed a homogenous, fine grain, and small pores appeared around the grain boundaries. The mechanical properties data showed improvement in the strength and hardness of the hot and cold compacted samples by increasing either the compaction pressure or temperature.