激光清洗脉冲宽度对钛合金表面形貌的影响

Effect of Laser Cleaning Pulse Width on Surface Morphology of Titanium Alloy

采用激光清洗技术对TC4钛合金表面的污染物进行清洗,研究脉冲宽度对钛合金表面宏观形貌、微观形貌、三维形貌、化学成分以及平整性的影响。结果表明,当脉冲宽度为150 ps时,钛合金宏观表面均匀明亮,微观形貌与原始试样接近,氧含量下降,粗糙度相对较小,平整性较好。而脉冲宽度增加到1 ns以及5 ns后,试样表面发生二次氧化,氧含量有所升高,且可观察到试样表面出现大量的熔池形貌,熔池中心向下凹陷,四周凸起,并以约80%的重叠率规则排列,形成宏观上肉眼可见的激光清洗纹路。脉冲宽度越大,试样表面粗糙度越大,平整性越差。

The laser cleaning technology was used to clean contaminants on the surface of TC4 titanium alloy.The effects of pulse width on the macromorphology,micromorphology,three-dimensional morphology,chemical composition and surface flatness of the titanium alloy were studied.The results show that when the pulse width is 150 ps,the macrosurface of titanium alloy is uniform and bright,and the microstructure is similar to the original sample.In addition,the oxygen content on the surface of the sample decreases,and the roughness is relatively small,the roughness is better.When the pulse width increases to 1ns and 5 ns,secondary oxidation occurs on the surface of the sample,and oxygen content increases to some extent.A large number of molten pool morphology could be observed on the surface of the sample.The pool is recessed in the center and raised on all sides,and arranged regularly with an overlap rate of about 80%,forming the laser cleaning pattern visible to the naked eye macroscopic.The larger the pulse width,the larger the surface roughness and the worse the flatness.