(1. 桂林電子科技大學(xué) 材料科學(xué)與工程學(xué)院 廣西信息材料重點(diǎn)實(shí)驗(yàn)室，桂林 541004；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 通過(guò)室溫拉伸、金相顯微鏡、掃描電鏡和透射電鏡研究晶間和剝落腐蝕對(duì)T6態(tài)、RRA態(tài)和T73態(tài)7055鋁合金板材拉伸性能的影響。結(jié)果表明：腐蝕后板材的強(qiáng)度和伸長(zhǎng)率均降低，但伸長(zhǎng)率的降低程度比強(qiáng)度的降低程度更大；剝落腐蝕后的性能降低程度大于晶間腐蝕后的；腐蝕后，RRA態(tài)板材的強(qiáng)度最高，T73板材的伸長(zhǎng)率最高；剝落腐蝕后的T6態(tài)板材拉伸時(shí)發(fā)生脆性斷裂；T6態(tài)板材腐蝕后拉伸性能的降低程度最大，RRA態(tài)的其次，T73態(tài)的最小；板材腐蝕后，表層產(chǎn)生大量腐蝕缺口和沿晶微裂紋，增大拉伸過(guò)程的裂紋源數(shù)量，降低拉伸性能；晶界上第二相粒子的尺寸、分布狀態(tài)影響板材腐蝕后的損傷程度，進(jìn)而影響拉伸性能的下降程度。
關(guān)鍵字: 7055鋁合金；晶間腐蝕；剝落腐蝕；拉伸性能；晶界第二相
7055 aluminum alloys after different aging treatments
（1. Guangxi Key Laboratory for Information Materials, School of Materials Sciences and Engineering,
Guilin University of Electronic Technology, Guilin 541004, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of intergranular corrosion and exfoliation corrosion exposure on the tensile properties of T6-, RRA- and T73-treated 7055 aluminum alloy sheets were investigated by ambient tensile test, optical microscopy, scanning electron microscopy and transmission electron microscopy. The results show that the strength and elongation decrease after exfoliation corrosion, the drop percentage is significantly higher for the elongation than that for the strength. The drop percentage in the tensile properties after exfoliation corrosion is higher than that after intergranular corrosion. After corrosion, the strength is the highest for RRA-treated sheet, and the elongation is the highest for T73-treated sheet. For the T6-treated sheet subjected to exfoliation corrosion, brittle fracture occurs during tensile test. The drop percentage in the properties due to corrosion is the highest for the T6-treated sheet, intermediate for the RRA-treated sheet and the lowest for the T73-treated sheet. Many notches and intergranular microcracks are present on the surface of the sheet due to corrosion, and this increases the number of the crack sources, thus deteriorates the tensile properties. The size and distribution of the second phase at grain boundaries have influence on the degree of corrosion damage, consequently the drop percentage in the tensile properties.
Key words: 7055 aluminum alloy; intergranular corrosion; exfoliation corrosion; tensile property; grain boundary second phase
