摘要
针对提高飞机襟翼滑轨表面耐磨性能的问题,采用激光熔注(Laser melt injection,LMI)技术在TC4表面制备WC颗粒增强的金属基复合材料(Metal matrix composite,MMC)层。通过光学显微镜,SEM,XRD,EDS等设备研究了MMC层微观组织和相组成以及扫描速度对熔注层形貌的影响,结果表明,扫描速度对MMC层有重要影响,随着扫描速度的增加,热输入减小,熔池内对流减弱,WC颗粒团聚现象增加。MMC层主要由WC,TiC,Ti,W_2C和W相组成,其中TiC分布主要分为两种:以反应产物的形式存在于Ti基体中;以反应层的形式存在于WC颗粒周围。反应层存在方式对WC颗粒有钉扎作用,因此耐磨性能的提升更大。除此之外,研究发现MMC层不同区域微观组织和硬度值存在明显差异:熔注层下部,TiC枝晶数量较少且尺寸较小;熔注层中上部,TiC枝晶数量较多且尺寸较大;硬度值主要与WC颗粒的分布有关,MMC层的硬度从上部到热影响区成先上升再下降的趋势。
One of the inherent problems associated with aircraft flap track is the solution to improve its wear resistance.The laser melt injec-tion(LMI)process has been successfully used to prepare a single crystal WC particles reinforced metal-matrix composite on TC4alloy.The microstructure evolution and phase composition were investigated by optical microscope,SEM,XRD and EDS.In particular,the influence of scanning speed on the dimensions and morphology of MMC was examined.The results showed that the MMC is sensitive to the scanning speed.It was found that the MMC is mainly composed of WC,TiC,Ti,W2C and W phases.There are two types of TiC,one is a reaction product in the Ti matrix,another is a reaction layer around the WC particles.The reaction layer is more conductive to the wear resistance,because there is a pinning mechanism in WC particles.In addition,a significant difference in the microstructure and microhardness among MMC different zones was observed.
作者
宋袁曾
刘立君
齐超琪
李亚萍
高转妮
Song Yuanzeng;Liu Lijun;Qi Chaoqi;Li Yaping;Gao Zhuanni(Shanghai Aircraft Manufacturing Co. Ltd, Shanghai 201324, China;Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, Zhejiang, China;Nanjing University of Aeronautics and Astronautics,Nanjing 211106, China)
出处
《焊接》
2018年第11期44-49,67,共7页
Welding & Joining
基金
商用飞机制造工程技术研究中心创新基金项目(COMAC-SFGS-2017-36736)
