Al_(2)O_(3)掺杂钼合金的显微组织及电化学腐蚀行为研究  

Study on Microstructure and Electrochemical Corrosion Behavior of Al_(2)O_(3) Doped Molybdenum Alloys

作　　者：焦照临 徐流杰[1,2] 徐照宁 周玉成[2] 杨璐[2] JIAO Zhao-lin;XU Liu-jie;XU Zhao-ning;ZHOU Yu-cheng;YANG Lu(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471003,China;National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology,Luoyang 471003,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003

出　　处：《稀有金属与硬质合金》2022年第5期59-65,69,共8页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金项目(U1804124);国家重点研发计划项目(2020YFB2008400);河南省重点研发与推广专项(202102210014)。

摘　　要：研究了在3.5%NaCl溶液中,Al_(2)O_(3)掺杂对钼合金电化学腐蚀性能的影响,并分析了合金的腐蚀机理。结果表明:Mo-Al_(2)O_(3)合金的耐腐蚀性能显著优于纯钼,随着Al_(2)O_(3)含量的增加,Mo-Al_(2)O_(3)合金的耐腐蚀性能先提升后下降。在腐蚀过程中,Cl^(-)优先吸附于钼合金氧化膜的缺陷位置形成点蚀,随着电位的增大,点蚀沿晶界扩大成为腐蚀沟槽。Al_(2)O_(3)可细化钼晶粒,从而促进钼合金形成致密的氧化物薄膜,不易发生点蚀,从而提升钼合金的耐腐蚀性能;但当钼合金中Al_(2)O_(3)的体积分数达到1.6%时,Al_(2)O_(3)颗粒由于团聚长大,破坏了钼合金氧化膜的完整性,使其对合金基体的保护作用减弱,导致钼合金耐腐蚀性能下降。The effect of Al_(2)O_(3)doping on the electrochemical corrosion resistance of molybdenum alloys in 3.5%NaCl solution was studied,and the corrosion mechanism of the alloys was analyzed.The results show that the corrosion resistance of Mo-Al_(2)O_(3)alloys is significantly better than that of pure molybdenum,and it increases at first and then decreases with the increase of Al_(2)O_(3)content.During the corrosion process,Cl^(-)is preferentially adsorbed on the defect positions of the molybdenum alloy oxide film to form pitting.With the increase of potential,the pitting expands along the grain boundary to become corrosion grooves.Al_(2)O_(3)can refine the molybdenum grains to promote the formation of a dense oxide film of molybdenum alloys which is less easily prone to pitting,thereby improving the corrosion resistance of the molybdenum alloys.However,when the volume fraction of Al_(2)O_(3)in molybdenum alloys reaches 1.6%,the Al_(2)O_(3)particles agglomerate and grow larger,which destroys the integrity of the oxide film of the molybdenum alloy and weakens their protection of the alloy matrix,resulting in a decrease in the corrosion resis-tance of the molybdenum alloy.

关 键 词：钼合金 Al_(2)O_(3)掺杂 电化学腐蚀 腐蚀机理 氧化膜 显微组织 

分 类 号：TG146.412[一般工业技术—材料科学与工程]