Improving the Forming Quality of Laser Dynamic Flexible Micropunching by Laser Pre-Shocking.

Jindian Zhang,Kai Liu,Xiao Wang,Zongbao Shen,Yang Wang,Guoyang Zhou,Youyu Lin,Pin Li,Lei Zhang,Huixia Liu

doi:10.3390/ma13173667

Abstract

Laser pre-shocking (LPS) was introduced into the laser dynamic flexible micropunching process to refine the grain size of a workpiece to improve the forming quality of punched parts. T2 copper foils with five different grain sizes and seven different laser power densities with and without LPS were used for the experiment. The results showed that the grains are refined and the average surface roughness decreases after LPS. For copper foils annealed at 650 °C, the value of decreases from 0.430 to 0.363 µm. The increase in laser energy density and grain size leads to the deterioration of the fracture surface. LPS can improve the quality of the fracture surface. Compared with punched holes without LPS, the dimensional accuracy and shape accuracy of punched holes can be improved by LPS. When grain size is close to the thickness of the copper foil, the forming quality of the punched parts becomes uncertain, owing to the difference in the orientation of the initial grains. The instability of laser dynamic flexible micropunching can be reduced by LPS. Especially, the improvement of forming quality of the punched part brought by LPS is significant for the copper foils with coarse grains.

Highlights

Microelectromechanical systems (MEMS) are becoming increasingly important and widely used in the industry, owing to the growing demand for parts with microsize features
The results showed that the values of nanohardness in the laser-shocked region were increased by 58.13%, due mainly to the grain refinement
Experimental research on the effect of Laser pre-shocking (LPS) on the forming quality of punched parts after laser dynamic flexible micropunching was conducted in this study

Summary

Introduction

Microelectromechanical systems (MEMS) are becoming increasingly important and widely used in the industry, owing to the growing demand for parts with microsize features. The miniaturization of traditional macroplastic forming processes to meet demands for the large-scale, high-efficiency, and short-cycle machining of microparts is becoming a research hotspot [1]. Micromanufacturing methods, such as microdrawing [2], microforming [3], and micropunching [4], have emerged one after the other and play important roles in actual production. Numerous problems exist in the traditional microforming process, such as low processing efficiency, microforming device processing difficulties, and alignment accuracy control between the female die and male die Such problems can generate considerable limitations in the process of industrialization and industrial production.

Methods

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Discussion

Conclusion