AZ31B在腐蚀环境下的棘轮与低周疲劳性能研究

发布时间：2017-12-31 03:27

本文关键词：AZ31B在腐蚀环境下的棘轮与低周疲劳性能研究　出处：《天津大学学报(自然科学与工程技术版)》2016年08期 　论文类型：期刊论文

【摘要】：开发了适用于镁合金圆棒试样的在线腐蚀疲劳系统,通过在空气和磷酸盐缓冲液(PBS)中分别进行循环疲劳试验,研究了腐蚀环境对AZ31B棘轮和低周疲劳性能的影响.结果表明:在棘轮应变演化的3个阶段中,腐蚀环境下试样在瞬态阶段和稳态阶段的棘轮应变率与空气中的相似;镁合金的腐蚀速率和棘轮应变随应力幅值和平均应力的增大而增大,孪晶、退孪晶的出现使得试样对腐蚀环境的敏感性进一步增加;在腐蚀环境中,镁合金的疲劳寿命大幅缩减,与空气中的试验相比,寿命缩减率达到50%,~90%,;为了能够反映平均应力、应力幅值、腐蚀环境以及最大压应力对AZ31B的低周疲劳寿命的复杂影响,采用FP参数模型对AZ31B进行了寿命预测.基于修正的FP参数模型,较好地预测了AZ31B在腐蚀环境下的低周疲劳寿命.
[Abstract]:The fatigue system developed for the on-line corrosion of magnesium alloy round bar specimens, through the air and phosphate buffer (PBS) were circulating fatigue test, studied the effect of environment on corrosion and low cycle fatigue properties of the AZ31B ratchet. The results showed that in the 3 stages of evolution of ratcheting strain in the specimen under corrosive environment with similar rates in the air ratchet strain transient stage and steady stage; the corrosion rate of magnesium alloy and the ratcheting strain increases as the stress amplitude increases and the average stress increases, the twins, twins appeared back of the specimen to further increase the sensitivity of corrosion environment; in corrosive environment, the fatigue life of magnesium alloy significantly reduced, compared with the test in the air, life expectancy reduction rate reached 50%, ~90%; in order to reflect the mean stress, stress amplitude, maximum compressive stress corrosion environment and low cycle fatigue life of AZ31B complex The FP parameter model is applied to predict the life of AZ31B. Based on the modified FP parameter model, the low cycle fatigue life of AZ31B under corrosive environment is well predicted.

【作者单位】：天津大学化工学院;天津大学仁爱学院;
【基金】：国家自然科学基金资助项目(11172202) 教育部新世纪优秀人才资助项目(NCET-13-0400) 天津市自然科学基金资助项目(14JCYBJC16900)
【分类号】：TG146.22;O346.2
【正文快照】： 在目前临床应用的医用金属材料中,只有镁合金与骨骼的密度和弹性模量最相近,且镁合金可以避免植入材料的应力遮挡效应[1].同时,镁作为人体必需的微量元素之一,几乎参与人体内所有的新陈代谢过程,包括骨细胞的形成,加速骨愈合能力.并且,镁合金的可降解性使植入物省去二次手术取

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