| This experiment mainly explores the process of ZK60 magnesium alloy prepared by powder metallurgy method,studied the effects on the plastic of boost phase and rare earth elements add in ZK60 magnesium alloy.Thus,the main point of the experiment focused on the effect of room temperature and elevated temperature plasticity of ZK60 magnesium alloy by adding rare earth element Y.This experiment materials were prepared by powder metallurgy method,and the powder was cleaned and mixed by ball mill,explores the effects of different clean circumstance,rotational speed and ball mill time,process control agents on the properties of powder,further vacuum hot-pressing sintering after extrusion bar.Under the premise of no heat treatment,the room temperature tensile and high temperature tensile sample was taken,respectively.The elongation of adding 3wt% Y is 25% at 25? and 10-2s-1.The elongation of adding 5wt% Y is 120% at 350? and 10-3s-1.The elongation of adding 10wt% Y is remarkable 165% at 350? and 10-3s-1.The metallographic structures of the as-sintered,as-extruded and elevated temperature stretching states were also observed,and the SEM,XRD and EDS were used to analyze initial powder and all kinds of states.From testing results,the quality of initial powder was not very well,but the oxide layers were exfoliated after ball-milling treatment.The size of grain decreased with the weight of Y increased.And the plasticity was improved remarkably due to the formation of new 14 H long-period stacking ordered X-phase?Mg12YZn?and quasi-crystal I-phase?Mg3YZn6?with containing 1wt% Y,while X-phase and W-phase?Mg3Y2Zn3?formed with containing 3wt% and 5wt% Y at elevated temperature tensile testing.Finally,process system was constructed,and the conclusion is that the elevated temperature plasticity of ZK60 magnesium alloy increased with increasing weight of Y.However,the extremum value of content of Y is not known,which need to be explored deeply. |
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