Refined Microstructure and Mechanical Properties of a near Eutectic Al-Si-Fe Based Alloy Produced by a Powder Metallurgical Route

초록

A near eutectic Al-13Si-5Fe-1Cu-0.5Mg-0.9Zr (wt%) alloy was fabricated by a gas atomization technique and subsequent consolidation via an extrusion process. In the extrusion process, various extrusion ratios and temperatures were used to investigate the effect of extrusion parameters on the microstructure and tensile deformation behavior of the alloy. It was revealed that if the atomized powders were extruded under the condition of extrusion ratio of 15 and extrusion temperature of 670K, both Al5FeSi intermetallics having about 50 ~ 400nm in size and fine eutectic Si particles are uniformly distributed in the grains with the average grain size of 900nm. It was also revealed that the nanosized Al5FeSi intermetallic phases are thermally stable up to about 670K and can enhance the tensile strength at elevated temperatures.