摘要
TiC陶瓷相韧性好、润湿性好、热化学稳定性高、耐磨性好,在激光熔覆温度下几乎没有脆性第二相生成,是理想的增强相,但目前对其加入Ni基合金粉末进行激光熔覆的研究较少。在TLF3200TM三维激光焊接机上以不同的扫描速度在45钢表面激光熔覆Ni基TiC复合粉末,采用扫描电镜观察熔覆层形貌,采用硬度计测试熔覆层的硬度,采用磨损试验测试其耐磨性,采用极化曲线分析其耐蚀性,研究了扫描速度对激光熔覆层显微组织和性能的影响。结果表明:不同扫描速度得到的激光熔覆层组织均由熔覆区、界面结合区和基底热影响区组成;当扫描速度为5 mm/s时,熔覆层组织中细小的TiC颗粒均匀、弥散分布于熔覆区和热影响区,熔覆层磨损率最低为0.12 mg/mm2,维钝电流密度最小,为0.008 mA/mm2,钝化区间最大,为0.65 V,耐磨及耐蚀性最佳。
A three-dimensional laser welding machine was performed to prepare laser cladding Ni-TiC coating on 45 steel substrate.The morphology of as-prepared Ni-TiC coating was observed with a scanning electron microscope,and its hardness was measured with a hardness meter.Besides,the wear resistance of the Ni-TiC laser cladding coating was evaluated,and its corrosion resistance was examined based on measurement of polarization curve.Furthermore,the effect of laser scanning velocity on the microstructure as well as wear resistance and corrosion resistance of the Ni-TiC coating was investigated.Results indicated that the laser cladding Ni-TiC coatings obtained under different scanning velocity all contained cladding zone,interfacial bonding zone and heat affected zone.Particularly,the Ni-TiC laser cladding coating obtained at a scanning velocity of 5 mm/s contained fine TiC particulates uniformly dispersed in the cladding zone and heat affected zone;and in this case the laser cladding coating exhibited a wear rate of 0.12 mg/mm^2,a minimum passivation current density of 0.008 mA/mm^2,and a maximum passivation range of0.65 V,while it possessed the optimal wear resistance and corrosion resistance.
出处
《材料保护》
CAS
CSCD
北大核心
2014年第6期69-71,8-9,共3页
Materials Protection
