润滑方式对7075铝合金车削表面耐腐蚀的影响

摘要

7075高强度铝合金经常在大气环境中应用,极易发生腐蚀.7075铝合金零件配合表面需要经过切削加工而成形,其机械加工一般都是在干切削和微量润滑(Minimum Quantity Lubricant,MQL)条件下进行的.为了揭示出润滑条件对7075铝合金加工面耐腐蚀性的影响规律,进行了切削和腐蚀单因素实验.在不同的切削速度和进给量下,对直径30衄的7075铝合金棒料,进行干车削和MQL车削加工,然后对样件进行3个周期的盐雾试验,每个周期72 h.观察其腐蚀表面形貌,统计出腐蚀面积、蚀坑数量、腐蚀损伤平均深度和腐蚀损伤度DOP等特征参数,揭示出7075铝合金在不同润滑条件下车削表面的腐蚀规律.%7075 high strength aluminum alloy is easily to be corroded in atmosphere.In the mechanical manufacturing process,7075 aluminum alloy component surface was got through the dry and MQL machining method.In this paper,with differental cutting speed,and feed rate,both dry and MQL turning experiments were carried out with Φ30 mm 7075 aluminum alloy rod.After that,salt spray test was done for three cycles,each period was 72 hours.Then,the corrosion state of surface morphology was observed,and meanwhile the corrosion area,corrosion pits quantities,the degree of corrosion damage,the average depth and average diameter of corrosion pits were counted.Finally,the corrosion law of machined surface was revealed in the aluminum alloy turning application.