Effects of Temper on Exfoliation Corrosion of 7150 Alloy
Exfoliation corrosion (EFC) is prevalent on the 7150 alloy structure of aging airplane. The effects of temper on EFC are investigated by means of corrosion test on 7150 alloy with peak-aged (T6), over-aged (T73) and RRA (T77) status and transmission electron microcopy (TEM). The test results show that T77 temper is the best for EPC resistance, T73 temper is the next and T6 temper is the worst TEM shows that continuous η phase exists on the grain boundary of T6 temper. The grain boundary of T73 and T77 temper has precipitate free zone (PFZ) and dispersed η phase. The PFZ of T77 temper is thicker than T73 temper. The particles of η phase at the grain boundary of T77 temper are coarser than T73 temper. Based on the results of the test and TEM observation, we can draw a conclusion that microstructure on grain boundary area is the key factor to affect the EFC of 7150 alloy. The preferential anode of the continuous η phase precipitated on the grain boundary is the EFC root of T6 temper. The preferential anode of the continuous PFZ on the grain boundary is the EFC root of T73 and T77 temper. The wedging stress only produced by the insoluble corrosion product at the grain boundary of T77 temper is difficult to sustain EFC development.
EFC peak-aged over-aged RRA η phase PFZ matrix
Huang Changlong Wan Xiaopeng
Northwestern Polytechnic University.Xian 710072, China Guangzhou Civil Aviation College.Guangzhou 5 Northwestern Polytechnic University.Xian 710072,China
国际会议
2010 Asia-Pacific International Symposium on Aerospace Technology(2010 亚太航空航天技术研讨会 APISAT 2010)
西安
英文
801-804
2010-09-01（万方平台首次上网日期，不代表论文的发表时间）