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Laser indirect shock forming is a novel microfabrication technique to introduce 3D profiles in metallic thin films. Experiments were performed by allowing the laser-driven flyer to impact the thin film, which is placed above a micromould. The effects of laser energy and sample thickness on deformation mechanism were investigated experimentally. The experimental results show that increasing the laser energy could increase the deformation depth, but may induce fracture along the edges of the micromould when the laser energy is too high. Moreover, the target plate was completely sheared off for 10 µm copper when the pulse energy is 1200 mJ. So it can be found that the technique can also realize micro punching of metallic thin films. The transient deformation of copper foil impacted by laser-driven flyer is simulated in this paper. Experimental data obtained were then used to validate the corresponding simulation model. Good agreement has been obtained between the numerical simulation and the experiments under different laser energy. The rising temperature due to the adiabatic conditions is taken into account. And the strain distribution has been also calculated numerically. [ABSTRACT FROM AUTHOR]

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination. [ABSTRACT FROM AUTHOR]

Plasticine is widely used in the analysis of metal forming processes, due to its excellent material flow ability. In this study, plasticine is used as the soft punch to fabricate array micro-channels on metal sheet in the micro sheet stamping process. This is because plasticine can produce a large material flow after being subjected to force and through the material flow, the plasticine can cause the sheet to fill into the micro-channels of the rigid die, leading to the generation of micro-channels in the sheet. The distribution of array micro-channels was investigated as well as the influence of load forces on the sheet deformations. It was found that the depth of micro-channels increases as the load force increases. When the load force reaches a certain level, a crack can be observed. The micro sheet stamping process was also investigated by the method of numerical simulation. The obtained experimental and numerical results for the stamping process showed that they were in good agreement. Additionally, from the simulation results, it can be seen that the corner region of the micro-channel-shape work piece has a risk to crack due to the existence of maximum von Mises stress and significant thinning. [ABSTRACT FROM AUTHOR]