7A52铝合金及其焊接接头冲击韧性研究

Research on the impact toughness of 7A52 aluminum alloy and its welded joints

研究了不同温度下7A52铝合金及其焊接接头冲击韧性的变化规律。用JBN-300B半自动冲击试验机测试了材料的冲击韧性,用S-3400N扫描电子显微镜观察了冲击断口的表面形貌。结果表明:同一温度时,由焊缝到热影响区再到母材的冲击韧性依次升高。同一区域在不同温度时,韧性变化均不明显,母材、热影响区和焊缝的冲击韧性在40℃较高,分别为26.3,18.8,9.6 J/cm2;在-20℃较低,分别为22.9,13.8,6.2 J/cm2。扫描电镜观察发现,7A52铝合金及其焊接接头断口均为韧窝断口,韧窝形状和数量有所不同。

An research on the impact toughness of 7A52 aluminum alloy and its welded joints at low temperature was carried out in the paper.The impact toughness of specimen was tested by impact test equipment of JBN-300B,and the fracture appearance was observed by SEM of S-3400N.The results showed that the impact toughness was increased from weld metal(WM),HAZ to base metal(BM) in sequence at the same temperature.The impact toughness variation of each region was not distinct at the same temperature.The impact toughness of BM,HAZ and WM was superior at 40 ℃,and the test values were 26.3,18.8,9.6 J/cm2;The impact toughness was lower at 20 ℃,the corresponding test values were 22.9,13.8,6.2 J/cm2.The fracture appearance of each regions were dimple fracture,just the features and numbers were disaccord.