Mold Size Effect in Microscale Laser Dynamic Flexible Bulging Assisted by Laser Pre-Shocking

Micromachines

Yijun Fang¹  Zongbao Shen²  Pin Li²  Jindian Zhang²  Xijin Zhen³ 

[1] School of Agricultural Engineering, Jiangsu University, Zhenjiang 212013, China;School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China;Shipbuilding Technology Research Institute, Shanghai 200032, China;

关键词: microscale laser dynamic flexible bulging;    mold size effect;    laser pre-shocking;    necking;    forming uniformity;   

DOI  :  10.3390/mi13050757

来源: DOAJ

【 摘 要 】

The size effect seriously affects the forming quality of micro-formed parts in the field of micro-forming. This paper focuses on the influence of the mold size effect in microscale laser dynamic flexible bulging (μLDFB). The experimental results indicate that, for the copper foil with a given thickness, there are suitable mold characteristic sizes to obtain better forming quality. The surface quality of bulging parts is poor when the mold characteristic size is small. However, the forming symmetry and forming uniformity of bulging samples are reduced when the mold characteristic size is large. As the laser pulse energy increases, the plastic strain increases, and the bulging samples experience five stages: uniform plastic deformation, local necking, cracks in the bulging zone, complete fracture in the bulging zone and complete rupture at the mold entrance zone. The increase of the surface roughening rate caused by the increase of grain size and mold characteristic size makes local necking easier, which further leads to fracture. On this basis, in this paper laser pre-shocking (LPS) is introduced to improve the forming quality. Comparative experiments show that LPS has a positive effect on improving the surface quality and the forming performance of bulging samples. The forming limit of bulging samples is increased and the occurrence of local necking is delayed.

【 授权许可】

Unknown