THE FORMATION, STRUCTURE AND CORROSION BEHAVIOR OF CONVERSION COATINGS ON ZINC ALLOY ELECTRODEPOSITS

被引：22

作者：

ABIBSI, A ^{[1
]}

SHORT, NR ^{[1
]}

DENNIS, JK ^{[1
]}

机构：

[1] UNIV ASTON,FAC ENGN,BIRMINGHAM B4 7ET,W MIDLANDS,ENGLAND

来源：

TRANSACTIONS OF THE INSTITUTE OF METAL FINISHING | 1991年 / 69卷

关键词：

D O I：

10.1080/00202967.1991.11870891

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

Zinc alloy electrodeposits containing 0 to 25% of Ni or Co have been prepared in the laboratory and carefully characterised with respect to composition and structure. A selected range of commercially produced deposits were obtained and similarly characterised. All these electrodeposits were conversion coated in a laboratory formulated solution and two solutions used in commercial processes. Rates of film formation were investigated by measurement of open circuit potentials on immersion in the various solutions, determination of coupon weight change and dissolution rates of Zn, Ni and Co. The composition and surface chemistry of the films were investigated using SEM with EDXA and XPS. Evaluation of corrosion behaviour was made using neutral salt spray and electrochemical tests. It has been found that the addition of Ni and Co to zinc electrodeposits decreased their activity and subsequent film formation in conventional chromating solutions, thus the requirement for special formulations. There is a considerable synergistic effect between the improvements found with alloying and the improvements found by conversion coating, this being attributed to the formation of superior barrier films.

引用

页码：45 / 49

页数：5