(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用硬度測試、晶間腐蝕試驗(yàn)，透射電鏡 (TEM)和高分辨透射電子顯微 (HRTEM)分析研究6時效和T6I6時效工藝處理對6005A鋁合金硬度和晶間腐蝕性能的影響。結(jié)果顯示：6005A鋁合金經(jīng)T6峰時效175 ℃、12 h后，雖然硬度達(dá)到了120 HV，但存在嚴(yán)重的晶間腐蝕傾向，腐蝕深度約為100 μm，同時，晶界上的析出相呈不連續(xù)分布，尺寸較小；經(jīng)T6I6時效處理后，晶內(nèi)生成細(xì)小的析出相，同時晶界的析出相呈不連續(xù)分布，但尺寸較大，此時合金可獲得更高的峰值硬度(127 HV)，而且其抗腐蝕能力得到顯著提高，腐蝕深度約為30 μm。
關(guān)鍵字: 6005A鋁合金；時效；β″相；腐蝕
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of T6 and T6I6 ageing treatments on the hardness and intergranular corrosion properties of 6005A aluminum alloy were investigated using hardness test, intergranular corrosion (IGC) test, transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) analysis. The results show that the hardness of the alloy in the T6 ageing treatment approaches a maximum value of 120 HV, however, it presents a severe intergranular corrosion with an average corrosion depth of 100 μm. The precipitates with small size are discontinuous at the grain boundaries. Fine precipitates with high density can be obtained in the grains after T6I6 aging treatment, and the precipitates are still discontinuous in the grain boundaries, however, the size of the precipitates is larger than that under T6 ageing treatment. The T6I6 ageing treatment for 6005A aluminum alloy not only increases the maximum hardness (127 HV), but also enhances the intergranular corrosion resistance, and the corrosion depth is only about 30 μm.
Key words: 6005A aluminum alloy; aging treatment; β″ precipitates; corrosion
