激光熔覆Fe基TiB_2+TiC金属陶瓷层的组织及摩擦磨损性能

Microstructure as well as Friction and Wear Behavior of Laser Cladding Fe /TiB_2-TiC Iron-Based Cermet Coating

目前,对激光熔覆原位自生金属陶瓷层增强相的形成机制及磨损机理的研究尚不系统。自配合金粉末,采用激光熔覆技术在Q235钢表面制备了原位自生的TiB2+TiC/Fe金属陶瓷层。对熔覆层进行了XRD分析、显微组织观察及室温干滑动摩擦磨损试验。结果表明:Fe基TiB2+TiC金属陶瓷增强熔覆层组织细小、致密,高硬度的亚微米TiB2和TiC金属陶瓷颗粒均匀弥散分布在α-Fe等轴枝晶基体上,熔覆层与基体冶金结合优良;室温下熔覆层的磨损主要为显微切削和滑擦,耐摩擦磨损性能优良。

Few systematical studies are currently available about the formation mechanism and wear mechanism of cermet coating reinforcing phases prepared by in-situ laser cladding. Thus alloy powders of TiB2-TiC were formulated at our laboratory and made into iron based cermet coating Fe / TiB2-TiC on the surface of Q235 steel by laser cladding. The phase composition and microstructure of as-prepared Fe / TiB2-TiC cermet coating were analyzed with an X-ray diffractometer and a scanning electron microscope,and its friction and wear behavior under dry sliding condition was also evaluated. Results indicated that the laser cladding la-yer of Fe / TiB2-TiC cermet coating was fine and compact.Sub-micron TiB2and TiC ceramic particles with high hardness were uniformly distributed in α-Fe equiaxed dendrite matrix,and strong metallurgical bonding was formed between the cladding layer and Fe-matrix. In the meantime,laser cladding Fe / TiB2-TiC cermet coating exhibited desired friction and wear behavior under room temperature,and its main wear mechanisms were micro cutting and scuffing.