变形温度对复合挤压ZK60镁合金组织与性能的影响

Effects of Deformation Temperature on Microstructure and Properties of ZK60 Magnesium Alloy Produced By Compound Extrusion

利用光学显微镜、扫描电镜、万能试验机等研究了变形温度对复合挤压ZK60镁合金组织与力学性能的影响。结果表明:经过不同温度复合挤压的ZK60镁合金晶粒细化,显微硬度、强度与塑性提高,拉压不对称改善。随着变形温度的下降,晶粒细化越明显,硬度值越高。200℃挤压试样的动态再结晶比较充分,晶粒细小,平均显微硬度达到77.8 HV,压缩屈服强度达到250 MPa,比挤压前分别提高20.6%与82.5%。250℃挤压试样的拉伸屈服强度为230 MPa,断后伸长率21.8%,比挤压前分别提高21.1%与24.6%。研究表明,复合挤压是一种有效提升镁合金性能的技术。

The effects of deformation temperature on the structure and mechanical properties of ZK60 magnesium alloy by compound extrusion were studied by means of optical microscope,scanning electron microscope and universal testing machine.The results show that the grain size of ZK60 magnesium alloy extruded at different temperatures is refined,the microhardness,strength and plasticity are increased,and the tension-compression asymmetry is improved.As the deformation temperature decreases,the more obvious the grain refinement is,the higher the hardness value is.The dynamic recrystallization of the extruded sample at 200℃ is sufficient,the grain is fine,the average microhardness reaches77.8 HV,and the compression yield strength reaches 250 MPa,which is 20.6% and 82.5% higher than that of the sample before extrusion.The tensile yield strength of the sample extruded at 250℃ is 230 MPa and the elongation after breaking is 21.8%,which is 21.1% and 24.6% higher than that before extrusion respectively.The above research shows that compound extrusion technology is an effective method to improve the properties of magnesium alloy.