MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SOLID STATE RECYCLED MG ALLOY CHIPS

Recycling of Mg alloy chips generated in machining processes such as turning and sawing through a melting process is difficult because the chips are very fine and can burn easily during heating. In this study, two machined Mg alloy chips were solid-staterecycled into a bar by hot pressing and hot extrusion, and the mechanical properties of the recycled chips were examined. The recycled AZ91 and AZX911 alloys showed a fine microstructure with a grain size of less than 10 p. m. The compressed yield stresses at room temperature were 208 and 210 MPa for the recycled AZ91 and AZX911, respectively, which are higher than those for non-recycled samples. A backward extrusion test revealed that the recycled AZ91 and AZX911 alloys have good forgeability at temperatures above 573 K and slightly higher hardness than non-recycled samples. Therefore, solid-staterecycled Mg alloys have good formability for forging at elevated temperatures with good mechanical properties and have potential for use as forging material