Interface microstructure and mechanical properties of selective laser melted multilayer functionally graded materials  

激光选区熔化成型多层结构功能梯度材料的界面组织和性能

作　　者：WANG Di DENG Guo-wei YANG Yong-qiang CHEN Jie WU Wei-hui WANG Hao-liang TAN Chao-lin 王迪;邓国威;杨永强;陈杰;吴伟辉;王皓亮;谭超林(.School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China;School of Intelligent Engineering,Shaoguan University,Shaoguan 512005,China;School of Mechanical Engineering,Dongguan University of Technology,Dongguan 523830,China)

机构地区：[1]School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China [2]School of Intelligent Engineering,Shaoguan University,Shaoguan 512005,China [3]School of Mechanical Engineering,Dongguan University of Technology,Dongguan 523830,China

出　　处：《Journal of Central South University》2021年第4期1155-1169,共15页中南大学学报（英文版）

基　　金：Project(2020B090922002)supported by Guangdong Provincial Key Field Research and Development Program,China;Projects(51875215,52005189)supported by the National Natural Science Foundation of China;Project(2019B1515120094)supported by Guangdong Provincial Basic and Applied Basic Research Fund,China。

摘　　要：Functionally graded material(FGM)can tailor properties of components such as wear resistance,corrosion resistance,and functionality to enhance the overall performance.The selective laser melting(SLM)additive manufacturing highlights the capability in manufacturing FGMs with a high geometrical complexity and manufacture flexibility.In this work,the 316L/CuSn10/18Ni300/CoCr four-type materials FGMs were fabricated using SLM.The microstructure and properties of the FGMs were investigated to reveal the effects of SLM processing parameters on the defects.A large number of microcracks were found at the 316L/CuSn10 interface,which initiated from the fusion boundary of 316L region and extended along the building direction.The elastic modulus and nano-hardness in the 18Ni300/CoCr fusion zone decreased significantly,less than those in the 18Ni300 region or the CoCr region.The iron and copper elements were well diffused in the 316L/CuSn10 fusion zone,while elements in the CuSn10/18Ni300 and the 18Ni300/CoCr fusion zones showed significantly gradient transitions.Compared with other regions,the width of the CuSn10/18Ni300 interface and the CuSn10 region expand significantly.The mechanisms of materials fusion and crack generation at the 316L/CuSn10 interface were discussed.In addition,FGM structures without macro-crack were built by only altering the deposition subsequence of 316L and CuSn10,which provides a guide for the additive manufacturing of FGM structures.功能梯度材料(FGM)可以在零件的不同区域定制其特性,例如耐磨性、耐腐蚀性和环境适应性。激光选区熔化(SLM)在制造FGM上具有出色表现,故本文采用SLM技术制备了316L/CuSn10/18Ni300/CoCr四种材料的FGM,研究了FGM的微观结构和性能,以揭示SLM加工参数对缺陷的影响。在316L/CuSn10界面处发现了许多微裂纹,这些裂纹自316L区域的熔合边界萌生并沿成型方向延伸。18Ni300/CoCr熔合区的弹性模量和纳米硬度显着下降,低于18Ni300和CoCr区域的弹性模量和纳米硬度。铁元素和铜元素在316L/CuSn10熔合区充分扩散,而CuSn10/18Ni300和18Ni300/CoCr熔合区中的元素则表现出明显的梯度转变。与其他区域相比,CuSn10/18Ni300界面和CuSn10区域具界面结合区域有明显的尺寸膨胀。最后,本文重点讨论了316L/CuSn10界面处的材料熔合和裂纹形成的机理。发现仅通过改变316L和CuSn10的沉积顺序就可以成型没有宏观裂纹的FGM,这为FGM的增材制造提供了指导。

关 键 词：selective laser melting multilayer functionally graded material interfacial characterization crack defects mechanical properties 

分 类 号：TB34[一般工业技术—材料科学与工程] TG665[金属学及工艺—金属切削加工及机床]