6063铝合金的多轴比例疲劳特性及其微观机理

Fatigue Characteristics and Microcosmic Mechanism of 6063 Aluminium Alloy Under Multiaxial Proportional Loading

摘要:

对6063铝合金进行多轴比例加载疲劳试验及微观结构观察,分析材料的疲劳特性及其微观机理.结果表明:随着等效应力幅值的提高,6063铝合金的疲劳寿命降低,材料的循环硬化现象逐渐明显,位错结构密度逐渐增大,位错由初步的交滑移结构演变为明显的迷宫状结构;使用MansonCoffin公式可对铝合金的多轴比例加载疲劳寿命进行准确的预测;位错结构是影响6063铝合金循环特性和疲劳寿命的主要因素.

Abstract:

Fatigue tests of 6063 aluminium alloy were performed under multiaxial proportional loading,and the fatigue characterristics and microcosmic mechanism were analyzed.Results indicate that the fatigue life is lower;the cyclic hardening is more obvious and the dislocation density is higher under higher effective stress amplitude,and dislocation structure changes from cross slipping to notable labyrinth.The fatigue life of aluminium alloy can be exactly forecasted by using equation Manson-Coffin under multiaxial proportional loading.The dislocation seriously affects the cyclic hardening and fatigue life of 6063 aluminum alloy.