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为了进一步提高钛合金表面改性层的质量,采用真空脉冲气体氮化法在不同温度下对工业纯钛TA2进行氮化处理。利用金相显微镜、扫描电镜、X射线衍射仪、硬度仪、摩擦磨损试验及极化曲线分析了氮化层的组织结构、耐磨性能、耐腐蚀性能和表面硬度梯度等,研究了氮化温度对氮化层性能的影响。结果表明:TA2钛合金经过不同温度氮化处理后,其表面主要形成Ti N_(0.3)相;氮化层厚度和表面硬度都随温度的升高而增加,当温度升高到900℃时,氮化层厚度达60μm,表面硬度达750 HV,耐磨性及耐蚀性较基材大幅提高,磨损速率由基材的0.277 8 mg/(h·cm~2)减小至0.000 4 mg/(h·cm~2),腐蚀速率降低了2个数量级;800~900℃温度范围内,氮化温度对氮化层的耐腐蚀性能影响不大,但是温度的升高使得表面组织变得粗大,同时脆性有所增加。
In order to further improve the quality of titanium alloy surface modification layer, the industrial pure titanium TA2 was nitrided at different temperatures by vacuum pulse gas nitriding. The microstructure, wear resistance, corrosion resistance and surface hardness of nitrided layer were analyzed by metallographic microscope, scanning electron microscopy, X-ray diffraction, hardness tester, friction and wear test and polarization curve. Effect on the performance of the nitride layer. The results show that TiN_ (0.3) phase mainly forms on the surface of TA2 titanium alloy after nitriding at different temperatures. The thickness of nitrided layer and surface hardness increase with increasing temperature. When the temperature rises to 900 ℃, The nitrided layer has a thickness of 60μm and a surface hardness of 750 HV. The wear resistance and corrosion resistance of the nitrided layer are much higher than those of the substrate. The wear rate decreases from 0.277 8 mg / (h · cm -2) to 0.000 4 mg / (h · cm ~ 2), the corrosion rate decreased by two orders of magnitude. In the temperature range of 800 ~ 900 ℃, the nitriding temperature had little effect on the corrosion resistance of the nitrided layer. However, the increase of temperature made the surface coarsened , While brittleness has increased.