【摘要】 钛合金属于粘性材料,易发生粘着磨损,为提高钛合金件作为摩擦副使用时的寿命,需提高钛合金表面硬度及耐磨性。利用连续激光器在TC4合金表面进行激光气体渗氮,生成金黄色的氮化层。用SEM、EDS、XRD分析试样渗氮层的微观组织、元素分布以及物质组成。结果表明,经激光气体渗氮后在TC4表面生成了以Ti N为增强相的改性层,并且在未渗氮区有黑色粉末状Ti N生成。表层由氮化层、热影响区及母材组成。渗氮层与基材发生冶金结合,结合强度高,不易剥落。随着激光功率的提升,渗氮层厚度及硬度都有所增加。当功率为1 200 W时,钛合金表面渗氮层最高硬度超过1 800 HV0.3,渗氮层厚度也最大。在氮气流量为10 L/min时整个渗氮层中氮元素的含量相对较高。经过激光气体表面渗氮后渗氮层的摩擦系数较基体材料摩擦系数有明显降低,耐磨性更好。更多还原

【Abstract】 In order to improve the life of titanium alloy,need to increase the surface hardness and wear resistance of titanium,for titanium belonging to viscous materials,prone to be adhesive weared.In this title,the TC4 is nitrided by continuous laser.A layer of golden nitrided layer is generated.With SEM,EDS and XRD,the micro-structure, elements distribution and compositions of nitriding layer are analyzed.The results show that titanium nitrided is generated;and some non-nitriding area is covered with black powder Ti N.The surface layer consists of the nitriding layer,heat affected zone and the substrate metal respectively.Nitriding layer and substrate are in a state of complete metallurgical bonding and the binding force is strong and not easy to peel off.With the rising of laser power,the hardness and thickness of nitriding layer increase,which are measured by micro-hardness meter.Due to the uneven distribution of Ti N,the hardness of nitriding layer fluctuates,which indicates that the microstructure and properties are corresponding.At the power of 1 200 W,the maximum hardness of titanium higher nitrogen content when the nitrogen flow is at the rate of 10 L/min.After laser gas nitriding,the friction coefficient of nitriding surface layer has a significantly lower than the base material,so the wear resistance is better.更多还原