激光熔覆制备Ti(C,N)颗粒增强金属基复合层的组织

Microstructure of Alloy Composite Coatings Reinforced by Ti(C,N) Particles through Laser Cladding Technology

采用高能束CO2激光在铸钢表面熔覆了含有碳氮化钛增强粒子的铁基熔覆层。利用X射线衍射(XRD)、金相显微镜(OM)和透射电镜(TEM)对激光熔覆层的微观组织进行分析与研究。结果表明:先前加入的颗粒状TiN与石墨粉在激光熔覆过程中发生了反应,原位自生了新的颗粒状强化相Ti(C0.3N0.7)。熔覆层中Ti(C0.3N0.7)的形貌特征多呈尺寸不等近似菱形颗粒及其他不规则形状,尺寸大小在0.1～3.0μm,它们弥散分布在熔覆层(α-Fe)基体中,基体组织呈现出胞状树枝晶特征,熔覆层与母材形成良好的冶金结合。Ti(C0.3N0.7)颗粒与熔覆层α-Fe基体间界面干净光滑,结合紧密。

A new in-situ synthesis method was employed to produce Fe-based alloy composite coating reinforced by Ti（ C,N） particles on the surface of cast steel through CO2 laser cladding technology. The phase compositions and the microstructure of the composite cladding layer were analyzed by X-ray diffraction（ XRD）,optical microscopy（ OM） and transmission electron microscopy（ TEM）. The results show that the Ti（ C0.3N0.7） particles are introduced by in-situ reaction between TiN particles and graphite powder added in advance during the laser cladding process,and most of the Ti（ C,N） particles in the cladding layer are irregular shape with the size of 0.1～3.0 μm and dispersively distribute in the substrate; The substrate of laser cladding layer contains cell and fine dendrite crystals,and the Ti（ C0.3N0.7） particles are tightly bonded to α-Fe（ substrate） in the cladding layer with clean and smooth bonding interface.