论文部分内容阅读
对2219-T8铝合金搅拌摩擦焊(FSW)接头在拉伸过程中,热机械影响区(TMAZ)的变形行为、断裂途径和190 MPa下微区电化学性能进行了研究.结果表明,焊接热循环和搅拌作用加权强化效果最弱的区域是强度最差的位置;拉伸时接头变形主要发生在TMAZ,但由于受到焊核区的拘束程度不同,TMAZ下层应变更大,导致裂纹起源于下层;在相同的应力水平下,TMAZ表面的钝化膜更易破裂,甚至会有微裂纹出现,这使得当接头处于应力腐蚀环境中时,TMAZ更易发生局部腐蚀,导致接头的抗应力腐蚀能力下降.
The deformation behavior of TMAZ, the fracture path and the electrochemical performance of the micro-zone at 190 MPa were investigated during the tensile process of 2219-T8 aluminum alloy friction stir welding (FSW) joint. The results show that the welding heat TMAZ was the main deformation in the TMAZ, but due to the different degree of restriction in the nugget zone, the strain in the lower TMAZ became larger, which resulted in the crack originated in the lower layer At the same stress level, the passivation film on the TMAZ surface is more prone to rupture and even micro-cracks appear. This makes the TMAZ more susceptible to localized corrosion when the joint is in a stress corrosion environment, resulting in a decrease in the stress corrosion resistance of the joint.