摘要
本文研究了深冷处理时间对Al-5Mg合金力学性能和硬度的影响。研究表明,Al-5Mg合金深冷处理时抗拉强度、断面收缩率和硬度在0~4 h范围内随深冷处理时间的增加而增大。深冷处理时间为8 h时合金的伸长率和断面收缩率显著提高,抗拉强度略有下降。深冷处理时间达12 h时合金抗拉强度和硬度提升显著,超过24 h后合金强度的提升变缓,硬度之提高开始变弱。提高Al-5Mg合金抗拉强度和硬度的最佳深冷处理时间为12~24 h。合金试样之深冷处理时间小于12 h范围,伸长率和断面收缩率有升有降,但深冷处理时间超过12 h后均随时间的延长而降低。就整体而言,试样深冷处理后伸长率和断面收缩率的改变分别不超过2.26%和4.16%,合金塑性最终趋于稳定。深冷处理提升Al-5Mg合金强度和硬度的机理是,在深冷处理条件下合金基体组织发生晶格畸变、位错增殖和缠绕,同时伴随β相之弥散析出。深冷处理8 h的试样出现塑性提高强度下降,其机理有待进一步深入研究。
The effects of deep cryogenic treatment time on mechanical properties and hardness of Al-5Mg alloy were studied by experiments.The results shew that the tensile strength,section shrinkage and hardness of Al-5mg alloy increased with the augment of deep cryogenic treatment time in the range of 0~4h.When the deep cryogenic treatment time was 8 h,the elongation and section shrinkage of the alloy increased significantly and the tensile strength decreased slightly.The tensile strength and hardness of the alloy increased markedly when the deep cryogenic treatment time reached 12 h.After 24 h,the alloy strength added slowly and the hardness began to weaken.The best time of deep cryogenic treatment was 12~24 h to improve the tensile strength and hardness of Al-5Mg alloy.When deep cryogenic treatment time was less than 12 h,the elongation and the section shrinkage of Al-5Mg alloy samples might increase or decrease.But after 12 h,the elongation and the section shrinkage decreased with the extension of time of deep cryogenic treatment.On the whole,after deep cryogenic treatment,the elongation and section shrinkage of the samples changed no more than 2.26%and 4.16%,respectively,and the alloy plasticity finally tended to be stable.The mechanism on the enhancement of strength and hardness of the alloy was that lattice distortion,dislocation multiplication and winding occurred in the matrix of the alloy under the condition of deep cryogenic treatment,meanwhile,theβphase is precipitated dispersively.After 8 h of deep cryogenic treatment,plasticity of the alloy increased but strength of one decreased,and its mechanism needed to be further researched.
作者
吉学英
晋芳伟
Ji Xue-ying;Jin Fang-wei(Research Institute of Bijie Circular Economy,Guizhou University of Engineering Science,Bijie 551700,China;School of Mechanical Engineering,Guizhou University of Engineering Science,Bijie 551700,China)
出处
《内燃机与配件》
2023年第21期9-12,共4页
Internal Combustion Engine & Parts
基金
贵州省科技支撑计划项目(黔科合支撑[2019]2870)
贵州省教育厅自然科学研究项目(黔教合KY字[2018]395,黔教合KY字[2019]053)
贵州工程应用技术学院高层次人才科学研究项目(G2018008)。
关键词
AL-MG合金
深冷处理
力学性能
硬度
Al-Mg alloy
Deep cryogenic treatment
Mechanical properties
Hardness
