形变热处理ZK60镁合金抗弹性能研究

Anti-penetration property of thermomechanical treated ZK60 magnesium alloy

以变形镁合金中比强度最高的ZK60合金作为研究对象,进行ZK60合金形变热处理实验研究,并以热变形态、热变形+T5态、热变形+T6态3种不同热加工态ZK60合金作为靶板材料,通过高速冲击实验,进行ZK60合金抗弹性能影响研究。结果表明:300℃热压缩变形后ZK60合金抗拉强度平均提高35 MPa、伸长率平均提高9%;变形+T5处理后合金抗拉强度下降约为18 MPa、伸长率下降约为2.6%;变形+T6处理后合金的抗拉强度最低,为241 MPa,而伸长率最高,达到33.8%;相同冲击速度下,变形+T5态靶板对应的弹坑周围不出现裂纹、合金抗弹性较好,变形+T6态靶板对应的弹坑周围有明显纵向裂纹、合金抗弹性较差,而变形态靶板所对应的弹坑形貌则具有不同特征,弹坑形貌与靶板材料的力学性能相关;通过线性回归,建立了弹坑深度与靶板材料常规力学性能之间的关系式。

ZK60 alloy was chosen for investigation because of its highest specific strength in wrought magnesium alloys. Experimental studies of hot deformation and heat treatment for ZK60 alloy were carried out. Anti-penetration property of ZK60 alloy under high impact loading was studied for three different hot working states targets. The results show that after hot compression deformation under 300 ℃, tensile strength of ZK60 alloy is improved by 35 MPa and elongation is improved by 9% on avecage. After T5 treating and deformingl tensile strength of ZK60 alloy is decreased by 18 MPa and elongation is decreased by 2.6% on average. After T6 treating and deforming, tensile strength is decreased to the lowest value 241 MPa, while elongation is increased to the highest value 33.8%. Under the same impact velocity, there is no cracks around the crater corresponding to T5 treated hot deformation ZK60 target, while there is obvious longitudinal cracks around the crater corresponding to T6 treated hot deformation ZK60 target. The morphology of the crater corresponding to hot deformation ZK60 target has different characteristic, which is associated with the mechanical properties of the target. Through linear regression, the linear fitting equation of the crater depth and mechanical properties of the target was given for reference.