镍铝青铜9442#合金及其冷喷涂涂层磨蚀行为

Tribocorrosion behavior of nickel aluminum bronze(NAB) 9442# alloy and its cold spray coating

摘要:

采用冷喷涂技术在镍铝青铜9442合金上制备了较为致密，厚度约300μm的镍铝青铜涂层，使用SEM、XRD、XPS、电化学工作站、磨蚀试验机观察并测试了镍铝青铜合金与涂层的组织形貌、电化学行为与磨蚀性能。结果表明：电化学腐蚀后基体发生了晶间腐蚀和选相腐蚀，涂层被腐蚀后颗粒上出现微孔和裂纹；磨蚀过程中存在着摩擦与钝化的协同作用以及摩擦促进阳极溶解的过程；相比于静态条件下，涂层与基体在磨蚀条件下测得的自腐蚀电位有大幅度下降，自腐蚀电流均提高了一个数量级，涂层与基体耐腐蚀性能变差；相比于干摩擦过程，磨蚀过程中涂层与基体的摩擦系数均有较大提高，减磨性能变差。

关键词:镍铝青铜;冷喷涂;电化学;磨蚀

Abstract:

Nickel aluminum bronze coating was deposited by cold spray technology on the nickel aluminum bronze 9442# substrate. Microstructure, electrochemical behavior and tribocorrosion behavior were observed and tested by SEM, OM, XRD, XPS, electrochemical working station and abrasion machine. The results showed that intergranular corrosion and optional corrosion took place in electrochemical corrosion process, microspore and cracks appeared on coating after electrochemical corrosion; tribocorrosion process consisted of competition between friction and passivation and promotion of anodic dissolution by friction; compared with static state, E_corrof coating and substrate under tribocorrosion condition drastically decreased, I_corrof coating and substrate increased an order of magnitude, corrosion resistance of coating and substrate became worse; compared with dry friction, friction coefficient of coating and substrate increased drastically, wear resistance of coating and substrate became worse.

Key words:nickel aluminum bronze; cold spray; electrochemical; tribocorrosion