时效处理对Al-0.78Mg-1.02Si-0.68Cu合金硬化行为及微观组织的影响  

Influence of Aging Treatment on Hardening Behavior and Microstructure of Al-0.78Mg-1.02Si-0.68Cu Alloy

作　　者：仲维锋[1] 庄利珍 滕敦波[1] 李辉[1,2] ZHONG Weifeng;ZHUANG Lizhen;TENG Dunbo;LI Hui(Yantai Nanshan University,Yantai 265713,China;National Engineering Research Center for Plastic Working of Aluminum Alloys,Shandong Nanshan Aluminum Co Ltd,Yantai 265700,China)

机构地区：[1]烟台南山学院,山东烟台265713 [2]山东南山铝业股份有限公司国家铝合金压力加工工程技术研究中心,山东烟台265700

出　　处：《有色金属工程》2019年第9期62-66,共5页Nonferrous Metals Engineering

基　　金：山东省高校科技计划(J18KA028);山东省重点研发项目(2017GGX20119);烟台重点研发计划(2017ZH081)~~

摘　　要：利用光学金相显微镜(OM)、能谱仪(EDS)、透射电子显微镜(TEM)、维氏硬度仪表征分析了预时效处理(PA)、自然时效(NA)和人工时效(AA)过程对Al-0.78Mg-1.02Si-0.68Cu合金的硬化行为及其微观组织演变。结果表明,预时效处理提高了T4P态的初期硬度,却明显弱化了NA硬化效应,T4态NA硬化值34HV,而T4P态只有25HV。180℃AA过程,显微硬度总体呈现先升高后降低的趋势,硬化曲线可以分为三个区域:20~60min之间硬化速率较高(Ⅰ);60~480min之间硬化速率较低(Ⅱ),在480min达到峰值硬度127HV;随后呈现降低的趋势(Ⅲ)。T4P态NA后,晶内为与基体共格的GP区;AA处理后,晶内主要为与基体半共格的亚稳η″析出相,晶界处存在长度15~40nm的不连续析出物和宽度45nm左右的PFZ区。The hardening behavior and microstructure evolution of Al-0.78Mg-1.02Si-0.68Cu alloy after Pre-Aging(PA) treatment, Natural Aging(NA) treatment, and Artificial Aging(AA) treatment were investigated by Optical Metallography (OM), Energy Dispersive Spectrometer(EDS), Transmission Electron Microscope(TEM)and Vickers hardness tester. The results indicate that PA treatment increases the initial hardness of the T4P state, but significantly weakens the NA hardening effect. The NA hardening value arrives 34 HV of T4 state, while the T4P state is only 25 HV. The micro-hardness generally increases first and then decreases with increasing aging time in the 180 °CAA process. The hardening curve could be divided into three regions: the hardening rate is higher between 20 and 60 min (I);the hardening rate is lower between 60 and 480 min (II), reaching a peak hardness of 127 HV at 480 min;followed by a decreasing trend (III). The coherent GP zones are the main phase after NA of T4P state;whereas semi-coherent η″ phase is the dominant phase after AA treatment. The discontinuous precipitation with a size of 15-40 nm and PFZ zone with a width of 45 nm exist at grain boundaries.

关 键 词：AlMgSiCu合金 时效处理 硬化行为 析出强化相 PFZ区 

分 类 号：TG166.3[金属学及工艺—热处理]