断续时效对Al-Cu-Mg-Ag新型耐热铝合金抗腐蚀性能的影响

摘要

The effects of the interrupted aging on the microstructure and the corrosion resistance of Al-Cu-Mg-Ag heat-resistant aluminium alloy were researched by intergranular corrosion (IGC),exfoliation corrosion (EXCO),electrochemical analyses and transmission electron microcopy analyses.The results show the precipitations both in the grains and on the grain boundaries are refined by interrupted aging.The coarse precipitations are distributed discontinuously on the grain boundaries of the single aged sample whose precipitation free zone (PFZ) is widened with some discontinuous precipitations.The fine precipitations are chain-like distributed on the grain boundaries of the interrupted aging sample and its PFZ is divided into two parts and correspondingly,the corrosion passageway is decreased tor the interrupted aging sample.The corrosion resistance of Al-Cu-Mg-Ag alloy is enhanced by the interrupted aging.%采用晶间腐蚀、剥落腐蚀、电化学分析和透射电子显微分析技术等研究断续时效处理对Al-Cu-Mg-Ag新型耐热铝合金微观组织与抗腐蚀性能的影响.研究结果表明:断续时效处理能够细化合金晶内和晶界析出相.单级时效试样晶界粗大的析出相呈不连续分布,晶界结构相当于一个宽大的无沉淀析出相(PFZ)上不连续分布着粗大的析出相.断续时效试样晶界细小的析出相呈链状分布,将晶界两边的PFZ隔离成2部分,腐蚀通道变窄,腐蚀电流密度减小,合金的抗晶间腐蚀和抗剥落腐蚀能力均得到提高.