Fabrication of Magnesium Alloy AZ31B with High Strength and Ductility via Harmonic Structural Design

Abstract

Harmonic structural materials of magnesium alloy AZ31B were fabricated by powder metallurgy. In the harmonic structural materials, small grains surround large grains and both of high strength and high ductility can be generated. However, there is almost no report on harmonic structural materials of magnesium alloy. AZ31B powder with average particle size of 300 µm was mechanically milled using planetary ball milling for 270 ks. Powder particles after milling possess structures with large grains surrounded by small grains. The powder was sintered using spark plasma sintering (SPS) and then subjected to forging using SPS apparatus. Forged materials exhibited tensile strength (310.5 MPa) twice that of magnesium material fabricated from initial powder (IP) associated with high ductility (22.7％) as same as IP materials. High strength magnesium alloy with superior ductility was achieved by harmonic structural design.

Fig. 9　Tensile stress-strain curves of forged materials.