激光复合溶胶凝胶法制备TiC强化涂层的工艺研究

采用Nd…YAG激光对预置有溶胶凝胶法制备的TiO2/C混合粉末的45#钢表面进行激光强化实验,制备TiC增强强化涂层。研究了激光工艺参数以及TiO2/C的成分配比对强化层生成物相的影响,探寻生成TiC的最佳工艺组合和粉末材料的成分配比。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)测试方法对激光强化样品进行物相、显微组织以及元素分析。结果表明,能生成TiC的最佳工艺组合为激光电流250A,脉冲频率18Hz,脉冲宽度2.5ms,扫描速度为50mm/min,TiO2与C的物质的量比为1…5。在上述工艺条件下,可在45#钢表面原位合成TiC增强相,并获得TiC颗粒均匀分布的强化涂层。

Research on Technics of TiC Hardened Coating Prepared by Hybrid Process of Laser and Sol-Gel

Laser hardening experiments are performed by Nd…YAG laser on the surface of 45 steel with TiO2/C compound powder prepared by sol-gel to get TiC enhanced coating.The influence of laser parameters and ratio of the powder materials on phases of hardened coating are investigated to explore the optimum technics.The phases,microstructures and elemental analysis are tested by X-ray diffraction(XRD),scanning electron microscope(SEM) and energy dispersive spectrometer(EDS),respectively.The results show that the optimum processing parameters should be laser current of 250 A, pulse frequency of 18 Hz,pulse width of 2.5 ms,laser velocity of 50 mm/min,and the mole ratio of TiO2 and C should be 1…5.Under the above condition,TiC reinforcing phase can be in-situ synthesized on the surface of 45# steel and the hardened coating with TiC particles uniformly distributed can be obtained.