Microstructure and Mechanical Properties of Hot Extruded ZK61 Alloy Produced by Rapid Solidified Powder Metallurgy

The effects of powder consolidation and extrusion temperatures on the microstructure and the tensile properties of hot extruded ZK61 alloy powder were investigated. The powder was produced by the rapid solidification technique of spinning atomization. Consolidation of the powder was done using the spark plasma sintering process at 200, 300 and 400 degrees C. Hot extrusion was then performed at 250, 300 and 400 degrees C. The tensile properties were then evaluated and correlated to the Microstructural features, i.e. grain size. The results show that the use of rapidly solidified spinning atomized powder could lead to improved mechanical response as a result of the refinement of both grains and inter-metallic compounds which are obtained through the use of powder metallurgy process. Tensile properties of extruded rapidly soilidified powders showed much superior values compared to that of extruded cast ZK61 alloy.