Self-Nanocrystallization of Ti-6Al-4V Alloy Surface Induced by Laser Shock Processing

摘要:

应用激光冲击强化技术（也叫激光喷丸）对TC4钛合金表面进行处理。由于其作用过程产生的高幅值压力（GPa量级）、短脉冲（ns量级）、高应变率(>106s-1)使材料表面实现纳米级晶粒细化成为可能，进而进一步提高材料表面性能。同时，应用该技术在TC4钛合金表面实现纳米级晶粒细化较少有系统的研究与报道。采用Q触发钕玻璃激光器，在一定条件、一定参数下，实现了TC4钛合金的表面纳米化，并对其形成机理进行阐述与分析。在实现材料自纳米化的同时，没有引入其它杂质粒子，保持了原母材的成分稳定性，且表面微动耐磨损性能得到了提高。开展该技术的深入研究，也可为材料表面纳米化提供另一种可行的途径与方法

Abstract:

The surface treatment technique of laser shock processing (LSP), also known as laser peening, was applied to treat the surface of Ti-6Al-4V titanium alloy, which was widely used in many fields including aeronautic industry. The high pressure shock wave (GPa level) and high strain rate (>106 s-1) for laser shocking make it possible to realize the grain refinement even nanocrystallization on the surface of Ti-6Al-4V alloy to improve the performance of material. However, the investigations of self-nanocrystallization of Ti-6Al-4V induced by LSP are seldom reported by now. The advantages of LSP technique is high peak value power, short duration (nano second level), easily realizing and repeated operating. The pressure model of plasma shock was carried out considering the left absorbing layer for the LSP, which is in accordance with the practical situation with more accurate calculation results than previous model. The self-nanocrystallization of titanium alloy surface can be realized using the method of laser shocking. The results enrich the theoretical basis, present a practice method of self-nanocrystallization of material surface and no other impurities are introduced and the performance of fretting wear resistance is improved simultaneously