喷丸工艺对7075铝合金表面粗糙度的影响

Effects of shot peening process on roughness of 7075 aluminum alloy

为探讨7075铝合金构件表面粗糙度与喷丸工艺参数的关系,采用ABAQUS三维有限元模拟软件建立了单个玻璃弹丸的撞击模型,在有限元分析的基础上,根据所得到的单个弹坑的几何尺寸,提出了表面粗糙度特征值Ra的理论预测模型。针对不同的弹丸直径、喷射气压、喷嘴距离以及喷丸覆盖率等喷丸工艺参数下的粗糙度值Ra进行了理论预测,并与实际7075铝合金喷丸后的表面粗糙度Ra进行了对比。结果表明,粗糙度特征值Ra随弹丸直径和喷射气压的增加而增加;Ra随覆盖率的增加呈现先增加后减少的变化趋势;喷嘴距离在一定范围内的变化对Ra几乎没有影响;Ra的预测值与实测值吻合良好,预测模型具有较高的可靠性。

For discussing effects of parameters of shot peening on roughness of 7075 aluminium alloy components ,3 D finite elements software ABAQUS was adopted for modeling impacting of a single ceramic shot. Based on the analysis of ABAQUS, the prediction model of roughness Ra of impacted surface was put forward depending on dimensions of a single crater. The roughness was calculated according to different parameters of shot peening, such as di- ameter of shot, pressure of compressed air, space between the nozzles and shooting target surface coverage. The prediction was compared with the experimental one. The result shows that the roughness increases as diameter of shot or pressure of compressed air increases, and increases before it decreases as surface coverage increases. Besides, there is little influence on Ra when space between the nozzles and shooting target vary within a certain rage. The prediction of roughness is in good agreement with the experimental one, and the prediction model has higher reliability.