TA2表面激光氮化处理的研究  

Study on Laser Gas Nitriding on the Surface of Commercial Pure Titanium TA2

作　　者：付现桥[1] 韩彬[1] 王勇[1] 李鹏[1] 

机构地区：[1]中国石油大学机电学院材料系,山东东营257061

出　　处：《应用激光》2011年第3期219-223,共5页Applied Laser

基　　金：山东省自然科学基金资助项目(项目编号:ZR2009FM030)

摘　　要：采用DL-HL-T型5 kW CO_2快速横流激光器对TA2进行了激光气体氮化处理。采用光学显微镜、扫描电子显微镜、X射线衍射、能谱分析对激光氮化试样进行了微观组织、相组成分析;采用MH-3型显微硬度计和M283恒电位仪与M352测试分析软件对激光氮化试样进行了显微硬度、自腐蚀电位Ecorr和自腐蚀电流密度Icorr的测试与分析。研究结果表明:经过激光表面氮化处理,在TA2表面生成了以TiN为增强相的氮化区域。该区域由氮化层、热影响区和基体三部分构成,氮化层组织主要由TiN和α′-Ti组成,厚大约50μm,硬度比较均匀;热影响区分为两部分:靠近氮化层处为N在基体中的固溶体α′-Ti,靠近基体处为相变产生的细小针状马氏体。氮化层显微硬度高达HV0.01 1652.1,而基体仅为HV0.01 230。TA2激光气体氮化层的自腐蚀电位由基体的-210mV提高到-144mV,自腐蚀电流密度降低为TA2的1/10,提高了TA2的耐均匀腐蚀和局部腐蚀的性能。In this paper, the nitrided layers were fabricated by a DL-HL-T-type 5 kW continuous wave CO2 laser on the TA2 surface . This Thesis uses optical microscope （OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy spectrum analysis to analyze the microstructure and phase composition. The microhardness, free corrosion potential, free corrosion current density Icorr are measured and analyzed by the use of MH-3 microhardness tester, M283 potentiostat and M352 test and analyse software. The results show that： after laser surface nitfiding, the nitride area, reinforced by TiN, generated on the surface of TA2, which consists of the nitride layer, heat affected zone is divided into two parts： one of it is ot＇-Ti in which the N diffuse near the nitride layer, the other is the small needle-like martensite near the matrix. TiN nitride layer mainly composed of TiN and α＇-Ti, with about 50 p,m thickness and uniform hardness, heat affected zone mainly is small needle α＇-Ti. Nitrided layer hardness is up to HV0.01 1 652.1, while the matrix is only HVO.01 230. The corrosion potential of the nitrided layer from -210 mV of the base metal increased to-144 mV, the corrosion current density decreased to 1/10 of the base metal, which improved the uniform corrosion and localized corrosion resistance of the TA2.

关 键 词：激光技术 氮化层 钛合金 组织结构 显微硬度 耐蚀性 

分 类 号：TN249[电子电信—物理电子学]