Study on processing characteristics and mechanisms of thermally assisted laser materials processing

摘要： Nanosecond pulsed lasers have been widely applied to interact with and characterize many di?erent materials, and industrial users are exploring more avenues for various application processes. For the purpose of achieving broader application, the current challenge is to achieve a high processing e?ciency for laser materials processing. In this study, thermally assisted laser materials processing (TALMP), which introduces heat from an external source to increase the workpiece material's temperature and make it easier to carry out ablation or modi?cation, was developed and investigated. Moreover, to investigate the materials processing characteristics and mechanisms of TALMP, practical applications using TALMP, including surface ablation on WC-Co, and surface polishing on additive manufactured Ti-6Al-4V, were carried out. The results showed that TALMP can be successfully applied to various materials by di?erent laser materials processing applications. Due to the workpiece material's high temperature and heat content, the coupling between laser and target materials can be enhanced; thus, physical ablation and modi?cation for laser surface ablation can be achieved e?ectively. However, with a high o?set temperature, a little decrease of ablation accuracy and quality could occur, and a two-step approach is proposed to eliminate this unwanted e?ect. Moreover, this strategy is proven to be able to achieve the desired surface ablation with high e?ciency and high-quality surfaces. For thermally assisted surface polishing, due to higher temperature ?eld with long duration, a smoother and ?atter polished surface can be obtained more easily. The experimental results proved the superiority and versatility of TALMP.