喷丸对高强度变形镁合金ZK60-T5高周疲劳性能的影响-《郑州大学学报(工学版)》

文章信息/Info

Title:: Effect of shot peening on high cycle fatigue properties of high-strength deformed magnesium alloy ZK60-T5

作者:: 刘文才; 董杰; 翟春泉; 等.; 上海交通大学,轻合金精密成型国家工程研究中心,上海,200240;上海交通大学,金属基复合材料国家研究中心,上海,200240, 上海交通大学,轻合金精密成型国家工程研究中心,上海,200240

摘要:: 为了研究高强度变形镁合金ZK60经喷丸处理后的表面变形层微观组织结构的变化及其对高周疲劳性能的影响,首先对用半连续铸造的方法浇注的圆棒进行热挤压,挤压比为14,并对挤压棒进行T5热处理后加工成漏斗型疲劳试样,标记为ZK60-T5.然后对一部分疲劳试样进行喷丸处理,观察喷丸后试样表面变形层的微观组织变化规律,并研究喷丸处理后表面粗糙度、变形层的显微硬度和残余压应力对ZK60-T5镁合金高周疲劳性能的影响.结果表明:高强度变形镁合金ZK60-T5的最佳喷丸工艺为0.05 mmN,且经喷丸强化后,ZK60-T5镁合金表面变形层的微观组织发生了变化,疲劳强度由150 MPa提高到195 MPa,提高了30%,疲劳寿命得到显著提高,而在表面变形层残余压应力场的作用下疲劳裂纹源由表面被"驱赶"到表面强化层下.

Abstract:: In order to study the changes of the microstructure of the surface deformation layer of high-strength deformed magnesium alloy ZK60 after shot peening treatment and its effect on the high cycle fatigue performance, the round rod poured by semi-continuous casting was first hot extruded with an extrusion ratio of 14, and the extruded rod was processed into a funnel-type fatigue sample after T5 heat treatment, labeled ZK60-T5. The effects of surface roughness, microhardness and residual compressive stress of the deformation layer on the high cycle fatigue properties of ZK60-T5 magnesium alloy after shot peening treatment were studied. The results show that the optimal shot peening process of high-strength deformed magnesium alloy ZK60-T5 is 0.05 mmN, and after shot peening, the microstructure of the deformation layer on the surface of ZK60-T5 magnesium alloy changes, the fatigue strength increases from 150 MPa to 195 MPa, which is increased by 30%, and the fatigue life is significantly improved, while the fatigue crack source is "driven" from the surface to the surface reinforcement layer under the action of the residual compressive stress field of the surface deformation layer.