摘要
采用增材制造技术将异种材料沉积到常规生产的规则半成品零件上的混合制造方式是实现大尺寸复杂双金属结构材料高效制造的有效方式之一。而实现此目标的主要前提之一是保证良好的界面结合质量。因此,采用激光定向能量沉积(DED)技术将A131 EH36沉积到传统轧制的AISI 1045钢上制备双金属结构,并对包含界面区的微观组织演变、力学性能以及切削响应进行研究,同时探究了热处理对性能的影响。结果表明:A131 EH36/AISI 1045双金属结构内部形成了宽度约为0.5 mm的无裂纹和未熔合缺陷的过渡区,表现出了优异的界面冶金结合;过渡区内包含了相互嵌合的组织细化区、组织粗化区、双重热影响区和热影响区,并在热处理后消失;过渡区的硬度从AISI 1045一侧的(182.0±11.7)HV逐渐增加到了A131 EH36一侧的(297.1±20.1)HV,热处理后的过渡区的硬度波动显著降低,在190 HV上下波动;直接沉积的双金属结构的拉伸强度和屈服强度略高于较弱的AISI 1045钢,分别达到了(629.0±1.1)MPa和(471.4±9.2)MPa,延伸率为17.9%;热处理后,双金属结构的屈服强度和延伸率分别提升了21.5%和23.5%;断口分析表明,双金属结构样品在远离界面区的一侧失效,表现为韧性断裂,且断裂后样品的原始界面区域没有出现裂纹和孔缺陷,展示了良好的界面结合性能;切削结果表明,DED A131 EH36的切削力比轧制的AISI 1045更平稳且低,最大切削力可降低64.1%,且前者的切削表面质量较好,表面粗糙度值为(107.0±10.4)nm,低于后者的(111.8±13.6)nm。
Objective Directed energy deposition(DED)not only inherits the high degree of freedom of the additive manufacturing technology,but also features a flexible material deployment.It can flexibly switch material types during the manufacturing process and precisely adjust the proportion of dissimilar powders,which enables high-efficiency manufacturing of large-scale multi-material parts.However,although the entire multi-material part can be easily fabricated using the DED process,the cost is relatively high when fabricating regular parts.A promising proposal is to manufacture regular parts using the traditional processes and fabricate complex parts using the DED process.By this,the purpose for improving efficiency and reducing manufacturing costs can be achieved while maintaining part performance.In this study,A131 EH36 steel is deposited on a commercial AISI 1045 steel using the DED process to verify the feasibility of a bimetallic structure by the hybrid DED and conventional processes as well as to reveal the interfacical binding mechanism.Furthermore,the effect of heat treatment on microstructure and mechanical properties of the bimetallic structure is also investigated.This research aims to explore a new way to improve the DED efficiency,reduce the costs,and provide theoretical and data supports for making full use of the performances of multiple materials.Methods The materials used in this study are the A131 EH36 powder and the AISI 1045 steel sheet.DED is used to deposit A131 EH36 on the AISI 1045 substrate.Quenching and tempering are performed to study the effect of heat treatment.Metallographic microscope and scanning electron microscope(SEM)are used for microstructural observation and fracture morphology observation.The elements are detected by an energy dispersive spectrometer.The porosity is determined using the image processing software(Image J).A Vickers microhardness tester is used to measure microhardness on the as-built and heat-treated samples.Quasi-static uniaxial tensile tests are conducted on a uni
作者
白玉超
王迪
李朝将
Bai Yuchao;Wang Di;Li Chaojiang(Faculty of Engineering,National University of Singapore,Singapore 117575,Singapore;School of Mechanic al and Automotive Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China;School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2022年第14期236-250,共15页
Chinese Journal of Lasers
基金
广东省基础与应用基础研究基金项目(2019B1515120094)。
关键词
激光技术
激光定向能量沉积
双金属结构
微观组织
力学性能
切削
laser technique
laser directed energy deposition
bimetallic structure
microstructure
mechanical properties
machining
