Synthesis and Microstructure Characterization of Fe-Cr-Al Alloys Developed by Powder Metallurgy Technique with Plasma Sintering Method

Abstract

Synthesis of Fe-Cr-Al alloy by powder metallurgy method was developed to produce a bioimplant material with a low modulus of elasticity. Microstructure characterization and phase identification were carried out to support the development of bone implant material research. The alloys were synthesized with the elemental composition of 16 Cr (wt%) that was added with Al in variations of 3, 6, and 10 (wt%). The synthesis was carried out by an exceptional combination of mixing and mechanical milling, cold compacting and consolidating with a special method using the APS (Arc Plasma Sintering) apparatus. Microstructure characterization and phase identification were analyzed by SEM-EDS and XRD tests. The microstructure showed relatively homogeneous fine grain with small porosity of around 80 %. Refinement of the XRD peak pattern revealed the formation of the Fe-Cr main phase followed by the Fe-Al phase with Al as the solid solution. The hardness test showed a high hardness level with a maximum for Fe-16Cr-6Al (wt%) of around 160 VHN (Vickers Hardness Number). The quantity of Fe-Cr phase and the composition of Al influenced the hardness of the alloy.