激光冲击过程中等离子体实际作用面积实验研究

Experimental Study on Actual Role Area of Plasma in Laser Shock Processing

为了研究激光冲击(LSP)过程中冲击波的实际作用面积,对涂敷新型吸收层的Al2O3陶瓷材料进行了冲击,通过烧蚀形貌的变化,分析了等离子体的横向膨胀效应刈实际冲击过程的影响;通过对0Cr18Ni9奥氏体不锈钢,3A21防锈锚合金的冲击过稃,分析了变形面积及深度的变化,验证了对不同材料而言,等离子体的膨胀效应具有普遍意义。结果表明,等离子体的膨胀与约束层材料有着直接的联系,在目前普遍使用的8mm直径的光束冲击下,若使用柔性约束,由于等离子体的膨胀,冲击波的实际作用面积直径约在12mm。

For studying the actual action area of shock wave in laser shock processing（LSP）, the Al2O3 ceramic materials have been impacted at new absorbing layer. The effect of horizontal inflation on actual shock processing is analyzed with the variety of ablation characteristic. The change of transforming area and depth is analyzed through the shock processing of 0Cr18Ni9 austenitic stainless steel and 3A21 antirust aluminum alloy, and the universality of the inflation effect is validated for different materials. It can be found that the inflation of plasma have direct contact with the material of confinement layer. The active function diameter of the shock wave is about 12 mm if the flexible coating is used with the light beam diameter of 8 mm.