镍基高温合金上Co改性铝化物涂层的组织结构与耐蚀性能

发布时间：2018-08-27 13:56

【摘要】：为研究Co改性铝化物涂层在室温环境中的耐蚀性,利用包埋法渗Co和气相沉积渗Al(两步法)制备出两种不同Co含量的Co改性铝化物涂层,采用XRD、SEM、EDS分析涂层的组织结构。结果表明:850℃和1 000℃渗Co涂层外层和内层均为γ-(Ni,Co)相,内层有氮化物/碳化物相析出。Co改性铝化物涂层与简单NiAl涂层结构一致,外层为β-(Co,Ni)Al相,内层为互扩散区含有大量的富Cr(W)相。简单NiAl涂层的自腐蚀电流为0.04μA/cm2,约为Co改性铝化物涂层的十分之一。这说明在涂层中添加Co降低涂层的耐蚀性,一方面因为Co的腐蚀电位(-0.28V)低于Ni的腐蚀电位(-0.25V),另一方面因为渗Co过程中产生的夹杂物与涂层电位不一致,容易成为微阴极区,加速涂层的腐蚀。
[Abstract]:In order to study the corrosion resistance of Co modified aluminized coatings at room temperature, two kinds of Co modified aluminized coatings with different Co content were prepared by embedding Co and vapor deposition Al (two-step method). The microstructure of the coatings was analyzed by XRD,SEM,EDS. The results showed that the outer layer and inner layer of Co coating were 纬-(Ni,Co) phase at 1 000 鈩，

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