钕钇铝石榴石脉冲激光表面熔凝后AISI 304不锈钢的微观结构演变及磨损行为

Microstructure evolution and wear behavior of AISI 304 stainless steel after Nd:YAG pulsed laser surface melting.

作者信息

Cui C Y, Shu Y X, Cui X G, Hu J D

出版信息

Appl Opt. 2020 Dec 1;59(34):10862-10869. doi: 10.1364/AO.406214.

PMID:33361907

Abstract

The microstructure and wear behavior of AISI 304 stainless steel after Nd:YAG pulsed laser surface melting (LSM) were investigated. The microstructural features of the LSM layer were characterized by field emission scanning electron microscope and high-resolution transmission electron microscope. Experimental results showed that the microstructure was obviously refined to the nano- and sub-micrometer scales on the AISI 304 stainless steel surface after LSM treatment. Fine grains with grain size of less than 200 nm were obtained when the applied laser energy densities were in the range of 1.90×10 to 3.52×10/ during LSM. The results indicated that the calculated surface temperature, cooling rate, and measured grain size are closely related to the adopted laser energy densities. The lower the laser energy density is, the lower the surface temperature, and the faster the cooling rate, the finer the grain size. In addition, the microhardness and wear resistance of the stainless steel was significantly improved. Finally, the wear mechanism after LSM process was revealed.

摘要

研究了Nd:YAG脉冲激光表面熔凝（LSM）处理后AISI 304不锈钢的微观结构和磨损行为。利用场发射扫描电子显微镜和高分辨率透射电子显微镜对LSM层的微观结构特征进行了表征。实验结果表明，LSM处理后AISI 304不锈钢表面的微观结构明显细化至纳米和亚微米尺度。在LSM过程中，当施加的激光能量密度在1.90×10至3.52×10/范围内时，可获得晶粒尺寸小于200 nm的细晶。结果表明，计算得到的表面温度、冷却速率和实测晶粒尺寸与所采用的激光能量密度密切相关。激光能量密度越低，表面温度越低，冷却速率越快，晶粒尺寸越细。此外，不锈钢的显微硬度和耐磨性显著提高。最后，揭示了LSM处理后的磨损机制。