反应火焰喷涂TiC/Fe复合涂层组织及形成机理

以TiFe粉和碳的前驱体（石油沥青）为原料通过前驱体碳化复合技术制备了Ti-Fe-C系反应喷涂复合粉末,并用普通火焰喷涂技术制备了TiC/Fe陶瓷金属复合涂层.观测了喷涂粉末、淬熄实验获取的飞行粒子以及涂层的形态、相和组织结构.结果表明：前驱体碳化复合Ti-Fe-C系喷涂粉末有非常紧密的结构;可有效的解决反应喷涂过程中原料粉末分离的问题.在反应火焰喷涂过程中,每一个喷涂粉末颗粒构成独立的微小反应单元,原料之间反应充分.在整个喷涂过程中喷涂粉末经历了熔化扩散、物相形成、碰撞后快速凝固三个阶段.所得涂层由TiC和Ti2O3共生聚集片层和细小TiC颗粒弥散分布于金属基体所形成的内晶型复合强化片层交替叠加而成.

Microstructure and forming mechanism of TiC/Fe composite coating by reactive flame spray

Ti/Fe/C composite powder for reactive spray was prepared using ferrotitanium and asphalt as raw materials.TiC/Fe composite coating was synthesized and deposited by reactive flame spray(RFS).XRD,SEM and EDS were employed to analyze the composition and microstructure of the composite powder and the coatings.The morphology of the powder particles that were quenched and gathered up was observed.The results show that the Ti/Fe/C composite powder for RFS has a very dense structure,which can avoid the problem that reactive constituent particles are separated during spraying.The each particle of Ti/Fe/C composite powders,acting as an independent reactive unit,respectively,form TiC/Fe composite coating after going through three successive stages:melt diffusion,phase formation and rapid solidification after collision.The TiC/Fe composite coating by RFS consists of alternate,laminated layers as following: the layers of TiC and Ti_2O_3 and the composite reinforcement layers in which the fne TiC particles are dispersed within the Fe-alloy matrix.