阵列式压电振子超声复合喷丸强化*

为了进一步改善超声喷丸强化质量,提升工件表面残余应力和显微硬度的均匀性,对压电振子阵列型超声喷丸强化加工系统进行了改进,提出了在强化加工过程中辅助工件往复运动的方法。对改进后的压电振子阵列型超声喷丸强化加工原理进行了阐述,分析了激振片的振动特性并进行了结构尺寸优化,应用Abaqus对工件往复运动下超声喷丸强化过程进行了仿真研究,分析了在不同的工件往复运动频率下,工件表面残余应力分布情况。实验测试了在不同喷丸强化时间及工件往复运动频率下超声喷丸强化加工质量,探究了喷丸时间和工件往复运动频率对工件表面显微硬度的影响。结果表明：在压电振子阵列型超声喷丸强化过程中辅助工件往返运动,可以有效提高工件表面残余应力和显微硬度分布的均匀性,工件表面强化质量得到提升。

Ultrasonic shot peening with piezoelectric vibrator array under reciprocating motion of workpiece

In order to improve the uniformity of residual stress and microhardness of workpiece surface after ultrasonic shot peening, the ultrasonic shot peening machining system with piezoelectric vibrator array has been improved, where the workpiece moves back and forth during ultrasonic shot peening machining. The working principle of the improved ultrasonic shot peening processing with piezoelectric vibrator array is described. The vibration characteristics of the vibration plate is analyzed and the structural size is optimized. The ultrasonic shot peening process is simulated by using Abaqus, and the residual stress distribution on the workpiece surface is analyzed under different reciprocating frequency of the workpiece. The ultrasonic shot peening processing quality is tested under different shot peening time and workpiece reciprocating movement frequency, and the effects of shot peening time and workpiece reciprocating movement frequency on the surface residual stress distribution uniformity and microhardness are investigated. The results show that the uniform distribution of residual stress and microhardness on the workpiece surface can be improved effectively by assisting reciprocating motion of the workpiece in the process of ultrasonic shot peening.