Research on Laser Peening of TC21 Titanium Alloy with High Energy Laser

摘要:

激光喷丸，又称为激光冲击强化（LSP），是一种新型表面处理技术，通过在材料表面诱导强烈塑性变形、产生高密度位错，产生较深的残余压应力，来提高材料的表面性能。采用LSP技术应用高能激光处理TC21钛合金。对材料的显微硬度、表面轮廓、冲击区表面粗糙度、残余应力进行了试验研究。结果表明：处理后，材料的显微硬度得到较大提高，冲击表面轮廓与冲击光斑大小直接相关，冲击区表面粗糙度(Ra)不超过0.8 μm，处理后，材料表面残余压应力水平得到了大幅度提高。经过LSP处理后，改善了材料的综合性能。

Abstract:

Laser peening (LP) also known as laser shock processing (LSP), is a surface enhancement technique that induces intensive plastic deformation, high dislocation density and deeper compressive residual stress to improve the surface performance of materials. The microhardness, surface profiles, roughness, and the residual stress of TC21 alloy were tested by LSP with high energy laser. The results show that the microhardness of the shocked area is improved apparently compared with that of unshocked area. The magnitude of dent is related with the diameter and the distribution of laser spot. The roughness Ra of shocked area is less than 0.8 μm. The compressive residual stress is enhanced greatly. The investigations show that the technology of LSP could further improve the performance of TC21 alloy.