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通过循环扩挤(CEEOP)变形方法对100 mm×50 mm×170 mm的AZ80镁合金块状材料进行挤压加工,借助计算机模拟仿真、组织观察、拉伸试验、硬度测试等手段研究了1~4道次CEEOP变形对AZ80镁合金等效应变、显微组织和力学性能的影响。结果表明:随着CEEOP挤压道次的增加,晶粒的尺寸越来越小且分布均匀,1道次后晶粒尺寸可以从200μm左右细化到6μm,4道次后晶粒尺寸细化到1.5μm左右,整体分布均匀呈等轴晶晶粒,晶粒细化的机制是晶粒的机械破碎和动态再结晶,2道次以后晶粒细化效果不太明显。力学性能较均匀化退火态有了大幅度的提升,1道次硬度HB从均匀化退火态的615 MPa提升到了830.7 MPa,4道次达到862.7 MPa,抗拉强度与屈服强度分别从均匀化退火态的230.9和115 MPa提升到了262.7和155 MPa,4道次可以达到294和170 MPa,通过对比ECAP变形试样的组织与力学性能数据,在相同的变形温度与累积应变下,CEEOP变形方法比ECAP变形能够更好地细化晶粒和提高材料的抗拉强度和屈服强度。
The extrusion process of 100 mm × 50 mm × 170 mm AZ80 magnesium alloy was carried out by means of cyclic expansion and extrusion (CEEOP) deformation method. With the help of computer simulation, microstructure observation, tensile test and hardness test, Effect of 4 - pass CEEOP Deformation on Equivalent Strain, Microstructure and Mechanical Properties of AZ80 Magnesium Alloy. The results show that with the increase of CEEOP extrusion pass, the grain sizes become smaller and more uniform, the grain size can be refined from 200μm to 6μm after 1 pass, the grain size is refined after 4 passes To about 1.5μm, the whole distribution of equiaxed grains is uniform, the mechanism of grain refinement is grain mechanical crushing and dynamic recrystallization, grain refining effect is not obvious after 2 passes. Mechanical properties of the annealed state has been significantly improved homogenization, HB hardness from a uniform annealed state of 615 MPa to 830.7 MPa, 4 times to 862.7 MPa, the tensile strength and yield strength were homogenized from the annealing 230.9 MPa and 115 MPa MPa were raised to 262.7 MPa and 155 MPa respectively, and 294 MPa and 170 MPa were achieved in 4 passes. By comparing the microstructure and mechanical properties of ECAP specimens, under the same deformation temperature and cumulative strain, the CEEOP deformation method ECAP deformation can better refine the grains and improve the tensile strength and yield strength of the material.