扩散温度对TC4合金表面Cu/Ni复合镀层结构及腐蚀性能的影响

Effect of temperature on the interface structure and corrosion ofCu/Ni coating on TC4 alloy

摘要:

论文采用扩散热处理研究了Cu/Ni/Ti复合镀层不同温度下的扩散行为，分析了扩散层结构，并讨论了扩散过程对镀层结构及腐蚀性能的影响。结果表明：由于Cu/Ni/Ti原子之间的互扩散，形成稳定的扩散层，可以有效提高镀层表面耐蚀性能；随着热扩散温度上升到700℃，膜层结构致密，在扩散层中形成了NixTiy金属间化合物及少量的CuxTiy金属间化合物，镀层表面的耐蚀性最好；温度升高到800℃时，在膜层界面处引发了Kirkendall效应，所形成的Kirkendall空位相互聚集长大，形成裂纹或孔洞，使得镀层疏松多孔，从而低了耐蚀性。

Abstract:

In this paper, the diffusion behavior of Cu/Ni/Ti atoms at different temperatures was studied by means of diffusion heat treatment. The influence of diffusion process on the structure and corrosion of the coating was also discussed. The results show that the corrosion resistance of the coating surface can be effectively improved with the stable diffusion layer formed by the mutual diffusion of Cu/Ni/Ti atoms. As the thermal diffusion temperature up to 700 ℃, the compact structure of membrane layer, the NixTiy intermetallic compounds and a small amount of CuxTiy intermetallic compounds formed in the diffusion layer, the corrosion resistance of coating on the surface of the best. Temperature to 800 ℃, Kirkendall space grew up together each other, which is formed by the formation of cracks or holes and make coating porous, so as to lower the corrosion resistance, due to Kirkendall effect is triggered by atoms at the interface between Cu/Ni/Ti structure.