摘要
以17-4PH不锈钢为基体材料,采用激光熔覆技术在不同激光功率(1600,1800,2000,2200 W)下制备了FeCoNiCrMo高熵合金/氧化石墨烯复合涂层,研究了复合涂层的显微组织、物相组成、显微硬度分布和耐腐蚀性能。结果表明,制备的FeCoNiCrMo高熵合金/氧化石墨烯复合涂层的微观组织由体心立方(BCC)固溶体和M_(23)C_(6)、M_(7)C_(3)、Co_(2)C等金属间化合物组成;随着激光功率的增加,金属间化合物形成的析出相增加,涂层耐腐蚀性能先增加后降低。当激光功率为2000 W时,涂层的硬度最高,且具有最佳的耐腐蚀性能,其自腐蚀电位为0.631 V,约为基体的2.66倍,自腐蚀电流密度为0.319μA/cm^(2)。激光功率是影响FeCoNiCrMo高熵合金/氧化石墨烯复合涂层组织及耐腐蚀性的显著因素,激光功率的增大促进了涂层中碳化物析出相的生长,有利于提高涂层硬度与耐腐蚀性能,但过高的激光功率下生成的大量硬质金属间化合物增大了涂层的裂纹敏感性,涂层产生明显裂纹,导致涂层耐腐蚀性能降低。
FeCoNiCrMo high-entropy alloy/graphene oxide composite coatings were prepared on 17-4 PH stainless steel substrate by laser cladding process with laser power of 1600,1800,2000 and 2200 W,and the microstructure,Composition of phase,microhardness and corrosion resistance of the coatings were investigated.The results indicate that the phase composition include solid solution with BCC structure and intermetallic compounds such as M_(23)C_(6),M_(7)C_(3) and Co_(2)C.With the increase of laser power,the number of dendrites formed by intermetallic compounds increases,the microhardness of the coating increases,and the corrosion resistance first increases and then decreases.When the laser power reaches 2200 W,the coating obtains the highest microhardness and the optimum corrosion resistance,the corrosion potential is 0.631 V,which is about 2.66 times that of the substrate,and the corrosion current density is 0.319μA/cm^(2).So it is found that the laser power is a significant factor affecting the microstructure and corrosion resistance of FeCoNiCrMo high entropy alloy/GO composite coating,and the increase of laser power promotes the growth of carbide precipitates in the coating,which is conducive to improving the hardness and corrosion resistance of the coating.However,excessive intermetallic compounds generated under high laser power increase the crack sensitivity of the coating,resulting in obvious cracks in the coating,and reducing the corrosion resistance of the coating.
作者
赵子硕
武美萍
缪小进
崔宸
龚玉玲
Zhao Zishuo;Wu Meiping;Miao Xiaojin;Cui Chen;Gong Yuling(College of Mechanical Engineering,Jiangnan University,Wuxi Jiangsu 214122,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第4期251-257,共7页
Heat Treatment of Metals
基金
江苏省机电产品循环利用技术重点建设实验室开放基金(RRME201902)
中央高校基本科研业务费专项基金(JUSRP121041)。
关键词
激光熔覆
高熵合金
激光功率
氧化石墨烯
耐腐蚀性能
laser cladding
high entropy alloys
laser power
graphene oxide
corrosion resistance
作者简介
赵子硕(1996-),男,硕士研究生,主要研究方向为激光熔覆表面强化,E-mail:dutzhaozishuo@163.com;通信作者:武美萍,教授,博士,E-mail:wumeiping163@163.com。
