Surface & Coatings Technology ( IF 5.4 ) Pub Date : 2020-06-29 , DOI: 10.1016/j.surfcoat.2020.126127 Qingqing Sun , Qingyou Han , Shuai Wang , Rong Xu
Microstructure, corrosion behaviour and thermal stability of ultrasonic shot peened AA7150 were studied in this work. After ultrasonic shot peening, exfoliation susceptibility decreases, intergranular corrosion is inhibited for both normal and transverse planes, pitting potential shifts to the positive direction. The enhanced localized corrosion resistance is attributed to the formation of equiaxed nano-grains on surface layer. Pre-existing ageing-induced η′ and η precipitates dissolved immediately after shot peening, however, after 18 months' natural ageing, nanograined precipitates with more coarsened size than pre-existing ones, re-precipitate on the peened surface layer and leads to surface softening.
中文翻译:
超声喷丸处理后AA 7150的组织,腐蚀行为和热稳定性
研究了喷丸AA7150的组织,腐蚀行为和热稳定性。超声波喷丸处理后,剥落敏感性降低,法向和横向平面的晶间腐蚀均受到抑制,点蚀电位朝正方向移动。增强的局部耐腐蚀性归因于表面层上等轴纳米颗粒的形成。喷丸处理后,预先存在的老化诱导的η'和η沉淀立即溶解,但是,在自然老化18个月后,纳米颗粒沉淀的粒度比先前沉淀的粗大,在沉淀的表面层上重新沉淀并导致表面软化。