Effect of Extrusion Wheel Velocity on Microstructure of AZ31 Magnesium Alloy Produced by Continuous Extrusion
The continuous extrusion tests of extruded AZ31 magnesium alloy were performed on 250 continuous extrusion machine.The microstructure before and after extrusion on the longitudinal section along extrusion direction were observed.The effect of extrusion wheel velocity on the microstructure of AZ31 magnesium alloy was investigated.The results indicate that the grain refinement is realized in continuous extrusion process;with the increase of extrusion wheel velocity,the grain size at the center region of products increases gradually;and the grain structure tends to become uniform in the surface and center regions when the extrusion wheel velocity is 7.0 r/min.