摘要
利用高能量的二氧化碳激光束在钢制的工件表面进行了激光熔覆改性处理,制备生成了含有碳氮化钛Ti(C,N)硬质相的复合熔覆层。在热力学分析的基础上,利用电子探针(EPMA)和X射线衍射(XRD),对熔覆层中原位生成的第二相粒子Ti(C,N)的形成机制进行了探究。研究结果表明,先前加入的颗粒状TiN在激光熔覆过程中首先发生了分解反应,而后生成了Ti原子和N原子,新生成的Ti原子再分别与C、N两原子发生化合反应,重新生成了碳化钛TiC和氮化钛TiN两种硬质相。TiC和TiN两者的晶体结构和晶格常数非常相似,它们相互固溶,原位生成了碳氮化钛Ti(C,N)连续固溶体,冷却凝固时新生成的碳氮化钛Ti(C,N)固溶体在熔覆层中以Ti(C_(0.3)N_(0.7))颗粒强化相析出。它们在熔覆层的基体内呈弥散分布,颗粒细小,形状不规则。
Fe-based alloy composite coating reinforced by Ti（C,N）particles was fabricated on the surface of work piece through high-energy CO2 laser beam.On the basis of thermodynamic analysis,electron probe microscopy analyzer（EPMA）and X-ray diffraction（XRD）were used to analyze the formation mechanism of in-situ generation of second phase particles Ti（C,N）in the composite coating.The results show that the previously in granular TiN in the laser cladding process decompose into Ti and N atoms.New Ti atoms combine reaction with C and N atoms respectively,carbides TiC and nitrides TiN two kinds of hard phase were formed.TiC and TiN have the similar crystal structure and the lattice constants,they form solid solution with each other,in-situ generation carbon titanium nitride Ti（C,N）solid solution in a row,cooling and solidification of new generation of carbon titanium nitride Ti（C,N）solid solution in the cladding coating with TiC0.3N0.7）particles strengthening phase precipitation.They were diffused in cladding coating matrix,particle tiny,irregular shape.
出处
《应用激光》
CSCD
北大核心
2016年第5期511-515,共5页
Applied Laser
基金
内蒙古高等学校包头职业技术学院科学研究项目(项目编号:Y201301)
