摘要
以Al、Ti和Ni/C混合粉末为原料,在AZ91D镁合金表面激光熔覆制备Al3Ti增强Al基复合涂层,并与基体和Al涂层进行对比。采用扫描电镜、X射线衍射仪对涂层的组织形貌和相组成进行分析,利用显微硬度计、电化学工作站对涂层硬度和耐腐蚀性进行测定。结果表明:Al涂层由Al3Mg2和Al12Mg17相组成,添加10%(Ti+Ni/C)涂层中还原位自生了增强相Al3Ti。与基体相比,涂层的硬度显著提高,耐腐蚀性有了明显改善。而与Al涂层相比,添加10%(Ti+Ni/C)涂层的平均硬度提高了41%,自腐蚀电位增加了167mV,自腐蚀电流密度略有下降,耐腐蚀性得到进一步提高。EIS测试结果显示,添加10%(Ti+Ni/C)涂层的Rc、Rct值均高于Al涂层和基体,证实了添加10%(Ti+Ni/C)涂层具有最好的耐腐蚀性。
Al3Ti reinforced Al-based composite coating was prepared by laser cladding on the surface of AZ91D magnesium alloy with Al,Ti and Ni/C mixed powder as raw materials,and compared with substrate and Al coating. Morphology and phase composition of the coatings were analyzed with scanning electron microscope and X-ray diffractometer. Hardness and corrosion resistance of the coatings were measured with microhardness tester and electrochemical workstation. The results show that the Al coating consists of Al3Mg2 and Al12Mg17 phases and the reinforcing phase Al3Ti is synthesized in situ in the coating with 10%(Ti+Ni/C). Compared with the substrate,the hardness and corrosion resistance of the coatings are significantly improved. Compared with Al coating,the average hardness of the coating with 10%(Ti+Ni/C) increased by 41%,the self-corrosion potential increased by 167 mV,the self-corrosion current density de-creased slightly,and the corrosion resistance is further improved. The EIS test results showed that the Rc and Rct values of the coating with 10%(Ti+Ni/C) are higher than that of Al coating and substrate,confirming that the coating with 10%(Ti+Ni/C) has the best corrosion resistance.
作者
靳坤
张英乔
张涛
郭杰
JIN Kun;ZHANG Yingqiao;ZHANG Tao;GUO Jie(Department of Materials Science and Engineering,North University of China,Taiyuan 030051,China)
出处
《电焊机》
2019年第10期83-87,共5页
Electric Welding Machine
关键词
激光熔覆
镁合金
显微硬度
极化曲线
阻抗谱
laser cladding
magnesium alloy
microhardness
polarization curve
impedance spectrum
