搅拌对沉积态2024铝合金组织与性能演变的影响  

Effect of Stirring on Microstructure and Properties of As-Deposited 2024 Aluminum Alloy

作　　者：吴凡 万桂林 杨洋 黄佳强 陈玮 孙中刚 Wu Fan;Wan Guilin;Yang Yang;Huang Jiaqiang;Chen Wei;Sun Zhonggang(AVIC Manufacturing Technology Institute,Beijing 100024,China;College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,Jiangsu,China)

机构地区：[1]中国航空制造技术研究院,北京100024 [2]南京工业大学材料科学与工程学院,江苏南京211816

出　　处：《中国激光》2022年第14期322-330,共9页Chinese Journal of Lasers

基　　金：航空科学基金(202000360T40001)。

摘　　要：利用搅拌摩擦技术,制备了不同工艺复合修复的激光熔化沉积2024铝合金,并且对这种复合工艺下制备的铝合金样品的显微组织和力学性能进行了研究。采用了直径为10 mm的搅拌头,搅拌摩擦工艺的旋转速度和进给速度分别为800 r/min和50 mm/min。利用光学显微镜和维氏硬度计研究了复合制造2024铝合金的显微组织和力学性能。结果表明:与激光熔化沉积相比,经过80%搭接率搅拌的2024铝合金的显微组织得到了细化,呈现梯度分布;时效处理后,基板区的硬度为135~140 HV,得到了显著提高,且经过搅拌后二次沉积的变形区域硬度可达到160 HV,同时随着沉积次数的增加,硬度出现梯度分布。Objective Carrying capacity is the core indicator of the value of a rocket.The weight of a rocket and its carrying capacity are trade-offs.Reducing the dead weight of a rocket and improving its structural efficiency are the keys to obtain a high carrying capacity.As an aerospace structural material,aluminum(Al)alloys are widely developed as aviation structural materials with a low melting point and high specific strength.Al alloys used as fuselage materials have become an important direction for future civil passenger aircraft material selection,and the laser melting deposition(LMD)technology needs to be developed urgently.The alloys have problems such as large hot cracking tendency and microstructural inhomogeneity that influence the properties of Al_(2)0_(24).In order to solve the problem of low strength of Al_(2)0_(24) alloys in additive manufacturing,the emerging friction stirring technology has been widely studied in which the Al_(2)0_(24) alloys are used.First,a two-layer gradient structure covered with a laser melting deposition layer and a stirring layer is fabricated on the substrate surface by combining the friction stirring technique.The resulting surface is then laser deposited.Friction stirring combining with laser cladding results in ultrafast laser hybrid fabrication.This gradient structure exhibits high strength,high toughness,and is resistant to fracture risk.Methods The diameter of the stirring head is 10 mm,and the friction stirring process parameters are the rotation speed of 800 r/min and the feeding speed of 50 mm/min.First,using the friction stirring technology,laser fusion deposited 2024 aluminum alloys repaired by different processes are prepared,and the microstructures and mechanical properties of Al alloy samples prepared by this composite process are studied.Next,the microstructures and mechanical properties of the composite-fabricated Al2024 alloys are studied with an optical microscope and a Vickers hardness tester to analyze the relationship between the process and their microstruct

关 键 词：激光技术 铝合金 增材制造 搅拌摩擦增材制造 人工时效 固溶处理 

分 类 号：TG146.2[一般工业技术—材料科学与工程]