激光合成Ni_3Al金属间化合物的腐蚀行为  

Corrosion Behavior of Ni_3Al Intermetallic Compound Synthesized by Laser Cladding

作　　者：王晋忠 郑乙 俞友军[2] 王凌倩[2] 

机构地区：[1]海军装备部,山西侯马043000 [2]中国科学院兰州化学物理研究所,甘肃兰州730000

出　　处：《材料开发与应用》2015年第2期52-57,共6页Development and Application of Materials

摘　　要：通过激光技术合成单Ni3Al相金属间化合物,利用电化学方法及盐雾试验研究了Ni3Al金属间化合物在Na Cl溶液中的腐蚀行为特征、耐腐蚀性能及腐蚀机理。结果表明:激光合成Ni3Al金属间化合物在不同浓度的Na Cl腐蚀介质中均能形成保护性钝化膜,当Na Cl溶液浓度低于2%时,钝化膜具有良好的稳定性和耐腐蚀性能。当Na Cl溶液浓度高于3.5%时,钝化膜产生活化溶解,稳定性下降,Ni3Al金属间化合物表面形成点蚀坑,并且随腐蚀介质浓度增大,腐蚀加剧。Ni3Al金属间化合物表面点蚀坑边缘规整、腐蚀界限清晰,腐蚀机制为典型的晶内腐蚀,腐蚀过程中未形成应力腐蚀微裂纹等破坏性缺陷,具备在沿海湿热盐雾环境下使用的潜在价值。Single Ni3Al intermetallic compound phase coating was successfully synthesized by laser cladding with preplaced Ni and Al mixed powders. Corrosion behaviors,corrosion resistance properties and corrosion mechanism of Ni3Al in NaCl solution were investigated by electrochemical and salt spray tests. It was found that the protective passive film could be formed on the Ni3Al surface in various concentration of NaCl solution and the passie film has a better stabihzation and protection property in the NaC1 solution below 2%. However, the passive film activated dissolved and its stability decrease, which leads to the formation of corrosion pits on the surface of Ni3Al in NaCl solution above 3.5% and the corrosion become more serious with increasing the concentration of NaGl solution. It is interested that the corrosion morphologies and boundaries around the corrosion pits are regular and clear with no corroded micro-cracks and destructive defects formed on the surface of Ni3Al, The corrosion mechanism of laser cladding Ni3Al intermetallic compound is the typical intragranular corrosion, which means that the laser cladding Ni3Al has a potential application in the hot and humid salt spray coastal environment.

关 键 词：NI3AL金属间化合物 激光合成 腐蚀行为 组织结构 

分 类 号：TG113.231[金属学及工艺—物理冶金]