CORRELATION BETWEEN MICROSTRUCTURE AND STRESS CORROSION CRACKING SUSCEPTIBILITY OF 2091 ALLOY
2091合金的显微组织与应力腐蚀敏感性

The stress corrosion cracking (SCC) susceptibility of an Al-Li-Cu-Mg-Zr al- loy (2091), heat-treated under different regimes, has been investigated by means of tensile test at slow strain rate. The microstructures has been examined with TEM. The deformation be- havior has also been analysed. The stress corrosion resistance of the alloy was revealed to be mainly affected by the covering of T_2-phase over grain boundaries and by the average dis- tance between T_2-phase particles. An improvement of SCC resistance may be obviously made by pre-deforming the alloy at room temperature to reduce the precipitation of T_2-phase along grain boundaries.