Effect of Micro-scale Y Addition on the Fracture Properties of Al–Cu–Mn Alloy

作     者：Ting-Biao Guo Feng Zhang Wan-Wu Ding Zhi Jia 

作者机构：School of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730050China Key Laboratory of Nonferrous Alloys and Processing of Ministry of EducationLanzhou 730050China 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2018年第31卷第6期

页      面：217-227页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Gansu Provincial Science and Technology Major Special Program Foundation of China(Grant No.1302GKDA015) State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Open Foundation of Lanzhou University of Technology of China(Grant No.SKL1303) 

主　　题：Al–Cu–Mn alloy Solid solution Fracture toughness Mechanical properties 

摘      要：Rare earth(RE) elements have positive e ects on Al alloy, while most research is focused on microstructure and mechanical properties. As important application indices, toughness and plasticity are properties that are sensitive to alloy fracture characteristics, and few research studies have characterized the fracture properties of Al–Cu–Mn alloy on RE elements. The e ect of di erent contents of Y on the fracture properties of Al–Cu–Mn alloy is investigated. T6 heat treatment(solid solution and artificial aging treatment), optical microscope(OM), scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS) methods are applied to the alloy. Results showed that when Y ele?ment is present at 0.1%, the section of the as?cast alloy has smaller sized dimples and the fracture mode presents duc?tile features. Slight changes in hardness are also observed and maintained at about 60 HV. With increasing content of the RE element Y from 0.1 to 0.5%, the θ phase and Cu atoms in the matrix were reduced and most stopped at Grain boundaries(GBs). Micro?segregation and an enriched zone of Y near the GBs gradually increased. At the same time, the inter?metallic compound AlCuY is aggregated at grain junctions causing deterioration of the micro?structure and fracture properties of the alloy. After T6 treatment, the flatness of the fracture surface was lower than that of all the as?cast alloy showing lots of dimples and teared edges with a significant increase in hardness. When Y content was 0.1%, the strength and hardness of the alloy increased due to refinement of the grain strengthening e ect. The content of Y elements segregated in the inter?dendritic zone and GBs is reduced. Plasticity and deformation compatibility also improved, making cracks di cult to form and merge with each other along adjacent grain junctions and providing an increased potential for ductile fracture. This paper proposes the addition of RE Y as an e ective and prospective strategy to improve the fra