不同腐蚀时间对DD6单晶高温合金表面形貌的影响  

Effects of Corrosion Time on Surface Morphology of DD6 Single Crystal Superalloy

作　　者：胡立杰[1] 李嘉荣[1] 刘世忠[1] 韩梅[1] HU Lijie LI Jiarong LIU Shizhong HAN Mei(Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China)

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《铸造技术》2017年第3期525-529,共5页Foundry Technology

摘　　要：研究了H_2O_2/HCl混合溶液中不同腐蚀时间对DD6单晶高温合金表面粗糙度及表面形貌的影响,使用表面粗糙度轮廓仪分析腐蚀前后合金的表面粗糙度,利用3D激光共聚焦扫描显微镜观察腐蚀前后合金的表面形貌,采用电子分析天平测定合金在不同腐蚀时间内的腐蚀速率,并探讨DD6合金在H_2O_2/HCl混合溶液中的耐腐蚀机制。结果表明:随着腐蚀时间的增大,DD6合金表面粗糙度呈现逐步增长规律;腐蚀后合金表面枝晶间区域出现腐蚀坑,随着腐蚀坑的扩大逐渐形成了腐蚀沟槽,枝晶干区域呈现凸出形貌;随着腐蚀时间的增大,合金的腐蚀速率先增大后降低;DD6合金的枝晶干与枝晶间的电势差异对腐蚀后合金的表面形态及腐蚀机制起到了决定作用。The effects of H2O2/HC1 mixed solution on corrosion resistance behavior of DD6 single crystal superalloy were investigated. The surface profilometer and laser confocal microscope were used to characterize the surface roughness and surface morphology, respectively. Electronic analytical balance was used to measure the corrosion rate. The results show that the surface roughness of DD6 alloy grows with the increase of corrosion time. After corrosion, pitting occurs in interdendritic region and then coalesces to form corrosion groove, finally protruding dendrite ann can be seen on the surface. The corrosion rate of DD6 alloy does not increase linearly with corrosion time, and the corrosion rate increases first and then decreases with the increase in corrosion time. The difference in surface potential between the dendrite and interdendritic region plays a critical role on the surface morphology and corrosion mechanism of DD6 superalloy.

关 键 词：DD6单晶高温合金 表面粗糙度 枝晶间腐蚀 点状腐蚀 

分 类 号：TG132.3[一般工业技术—材料科学与工程]