レーザピーニングにおけるアブレージョンによる衝撃力と気泡の崩壊衝撃力の比較

抄録

In order to enhance mechanical properties of metallic materials by surface improvement, laser peening using a pulse laser has been developed. There is two types of laser peening. One of them is that target with water film is exposed to the pulse laser, and the other method is that target in a water chamber is treated by the pulse laser. The latter laser peening method is called as “submerged laser peening”. For both laser peening, it was believed that impact induced by laser abrasion caused plastic deformation. However, in the case of submerged laser peening, bubble is developed after laser abrasion, and it produces severe impact at bubble collapse. In the present paper, impact induced by laser abrasion and impact at bubble collapse were evaluated by a handmade PVDF sensor which was placed in the target. It was revealed that the impact at bubble collapse was about 1.5 times larger than that of impact induced by laser abrasion.