【摘要】 利用大气气氛下激光氮化方法,采用CWCO2 激光作为辐射源,同时通以与激光束同轴的激活态氮束流,对工业纯钛进行氮化处理。并利用X射线衍射方法(XRD)对样品进行测试分析。结果表明,当激光功率密度不小于6. 5×105W·cm-2、扫描速度不大于600mm·min-1时,在大气气氛下可实现钛表面的氮化处理,且氮化处理后,钛的表面硬度可提高3倍左右。采用半无限大模型对氮化过程中的温度分布进行了数学模拟,并推导出了温度分布方程。由此方程出发,计算出了钛表面实现激光氮化时所需限制的最大扫描速度为600mm·min-1,并与实验结果进行了比较,结果发现,用该模型计算出的扫描速度的阈值与实验结果基本吻合。更多还原

【Abstract】 The pure titanium was nitrided by laser nitriding me th od in atmospheric ambient with the radiation of CW CO 2 laser.The activated nit rogen beam was introduced into the melting pool together with the laser beam.The samples were tested with X-ray diffraction(XRD) method.The results show that t he nitridation on the surface of titanium can be realized by choosing proper las er parameters,including laser power density,scanning speed and pre-heated treat ment to nitrogen gas.The minimum power density is 6.5×105W·cm -2 an d the maximum scanning speed is 600mm·min -1.The distribution of temperatu re field during the nitriding process is simulated with semi-infinity model.Fro m this model,the theoretical threshold of scanning speed is deduced to be 600mm ·min -1.This value is near to the experimental result.更多还原