Elucidation of solid-liquid-gas interfacial phenomena induced by pulse laser and its practical application

2021 Fiscal Year Final Research Report

• Project/Area Number: 18KK0103
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Soyama Hitoshi 東北大学, 工学研究科, 教授 (90211995)
• Co-Investigator(Kenkyū-buntansha): 伊賀 由佳 東北大学, 流体科学研究所, 教授 (50375119) ; 佐々木 裕章 東北大学, 工学研究科, 助教 (90812040) ; 鴇田 駿 東北大学, 工学研究科, 助教 (60807668)
• Project Period (FY): 2018-10-09 – 2022-03-31
• Keywords: キャビテーション / レーザキャビテーション / レーザアブレージョン / 機械的表面改質 / 疲労強度 / 金属製積層造形材

Outline of Final Research Achievements

The purpose of this study is to elucidate the solid-gas-liquid interface phenomenon that occurs when a pulsed laser is applied to a metal surface placed in water, and then applied for mechanical surface treatment. In this study, it was focused on the laser cavitation which is produced after laser ablation. In laser peening, it is thought that the impact force due to laser ablation is utilized, and there was no interest in laser cavitation, but the principal investigator found that the impact force due to laser cavitation is greater than that due to laser ablation. The improvement of fatigue strength of metal materials by surface modification using laser cavitation was demonstrated.

Free Research Field

表面力学設計

Academic Significance and Societal Importance of the Research Achievements

CAD/CAMデータから直接的に造形できるなどの利点から，金属製積層造形材が医工学用インプラントなどへの適用が期待されている。しかしながら，その疲労強度がバルク材の半分適度しかないことが実用化への障壁になっている。本研究では，パルスレーザを用いた固気液界面現象を解明して，パルスレーザで生じるレーザキャビテーションの衝撃力により金属製積層造形材の疲労強度を2倍以上向上できることを実証した。