Mechanical Characteristics of Hot Extruded Non-Combustible Magnesium Alloy using Water Atomized Powder

SWAP (Spinning Water Atomization Process), is one of the rapid solidification processes which promises to produce coarse non-combustible magnesium alloy powder with 1∼4mm length, having fine a-Mg grains and Al 2 Ca intermetallic compounds. AMX602 (Mg-6%Al-0.5%Mn-2%Ca) powders were compacted at room temperature. Their green compacts with a relative density of about 85% were heated at 573-673 K for 300s in Ar gas atmosphere, and immediately consolidated by hot extrusion. Microstructure observation and evaluation of mechanical properties of the extruded AMX602 alloys were carried out. The uniform and fine microstructures with grains less than 0.45∼0.8 μm from dynamic recrystallization during hot extrusion were observed, and were much smaller compared to the extruded AMX602 alloy fabricated by using cast ingots. The extremely fine intermetallic compounds 200∼500 nm diameter were uniformly distributed in the matrix of powder metallurgy (P/M) extruded alloys. These microstructures produced excellent mechanical properties in the wrought alloys. For example, in the case of AMX602 alloys extruded at 573K, the tensile strength (TS) of 447 MPa, yield stress (YS) of 425 MPa and 9.6% elongation were obtained.