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一、前言粉末冶金是少切削、无切削的新工艺之一。由于粉末冶金件是一个海绵体,内部包含着无数的微孔,因此给防护装饰性电镀带来了极大的困难。在电镀过程中,酸碱洗涤液和电镀液等吸附并积聚在微小的孔隙中,对包在外面的镀层起着极其危害的作用:(一)吸附的溶液将由镀层渗出成斑点或印痕,损坏了外观质量;(二)金属镀层与基本金属间在存有溶液的微孔中,形成了一个原电池;不断产生电解,加速了腐蚀作用,引起镀层脱皮起壳。
First, the preface Powder metallurgy is less cutting, cutting one of the new technology. As the powder metallurgy is a sponge, the internal contains numerous pores, so to protect the decorative plating has brought great difficulties. In the electroplating process, the acid-base washing liquid and the plating solution are absorbed and accumulate in tiny pores, which play an extremely harmful role on the coating on the outside. (1) The solution adsorbed will be exuded by the coating into spots or imprints, The quality of the appearance is damaged; (2) a galvanic cell is formed between the metal plating and the basic metal in the micropores in which the solution is stored; and the continuous electrolysis accelerates the corrosion and causes the coating to desquamate.