激光选区熔化制备CuSn10/AlSi10Mg功能梯度材料组织演变及裂纹产生机理  

Microstructure Evolution and Crack Formation Mechanism of CuSn10/AlSi10Mg Functional Gradient Materials Prepared by Selective Laser Melting

作　　者：何鑫 罗霞 汤金钢 赵庄 戴玉宏 黄本生[1] He Xin;Luo Xia;Tang Jingang;Zhao Zhuang;Dai Yuhong;Huang Bensheng(School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,Sichuan,China;Institute of Machinery Manufacturing Technology,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China;Chengdu Xin Shan Aerospace Technology Co.,Ltd.,Chengdu 610500,Sichuan,China)

机构地区：[1]西南石油大学新能源与材料学院,四川成都610500 [2]中国工程物理研究院机械制造工艺研究所,四川绵阳621999 [3]成都新杉宇航科技有限公司,四川成都610500

出　　处：《中国激光》2024年第20期213-224,共12页Chinese Journal of Lasers

基　　金：中国工程物理研究院科学挑战项目(TZ2018006-0303-01);国家自然科学基金(52376076)。

摘　　要：激光选区熔化(SLM)制备功能梯度材料(FGMs)可以对性能进行局部定制。通过SLM制备CuSn10/AlSi10Mg功能梯度材料,研究材料成分比对CuSn10/AlSi10Mg过渡层显微组织的影响。通过相图计算(CALPHAD)过渡层的物相及其数量,并结合背散射电子衍射仪(EBSD)结果讨论梯度材料界面区域组织演化规律,揭示界面区域裂纹的形成机制。结果表明,CuSn10/AlSi10Mg过渡层显微组织由基体、Al_(4)Cu_(9)相和Al_(2)Cu相组成,形貌呈柱状晶粒和细小等轴晶粒。在过渡层区(从铜合金侧到铝合金侧),随着AlSi10Mg含量的增加,基体含量变化不大,Al/Cu金属间化合物含量变化剧烈,Al_(4)Cu_(9)相先析出且含量逐渐减少,Al_(2)Cu相后析出且含量逐渐增加,裂纹周围有大量Al/Cu金属间化合物生成。过渡区域内产生宏观开裂的主要原因是直接生成的Al_(4)Cu_(9)相引起高体积变化(体积变化率为4.4%)容易首先在质量分数为0~20%的AlSi10Mg区域内形成应力集中,产生微裂纹;Al_(2)Cu相与基体中多余的铜转变为Al_(4)Cu_(9)相(间接生成),其引起的高体积变化(体积变化率为4.3%)在质量分数为80%的AlSi10Mg区域内进一步加重应力集中,从而造成宏观开裂。避免Al_(4)Cu_(9)的生成(直接和间接生成)是解决裂纹的主要途径。过渡层区域的显微硬度高于两侧基体,最高硬度在裂纹处(804 HV),与Al_(4)Cu_(9)的硬度相近。Objective Selective laser melting(SLM)can be used to prepare functionally gradient materials(FGMs)for local customization of performance.In this study,CuSn10/AlSi10Mg functional gradient materials were prepared by SLM,and the effect of the material composition ratio on the microstructure of the CuSn10/AlSi10Mg transition layer was investigated.The phase and quantity of the transition layer were calculated using CALPHAD,the microstructural evolution of the interface region of the gradient materials was discussed based on electron backscattering diffraction(EBSD)results,and the formation mechanism of cracks in the interface region was revealed.The results show that the microstructure of the CuSn10/AlSi10Mg transition layer consists of a matrix of Al_(4)Cu_(9) and Al_(2)Cu with columnar and fine equiaxed grains.In the transition layer zone(from the copper alloy side to the aluminum alloy side),with an increase in the AlSi10Mg content,the matrix content does not change significantly,whereas the content of Al/Cu intermetallic compounds changes sharply.The Al_(4)Cu_(9) phase first precipitates and its content gradually decreases,whereas the Al_(2)Cu phase precipitates later and its content gradually increases,and a large amount of Al/Cu intermetallic compounds are generated around the cracks.The main reason for the formation of severe cracks in the transition zone is that the directly generated Al_(4)Cu_(9) phase is prone to large volume changes(4.4%),leading to stress concentration and initial microcracks.The large volume change(4.3%)caused by the transformation of the Al_(2)Cu phase and Cu enriched in the matrix into the Al_(4)Cu_(9) phase(indirectly generated)further exacerbates the stress concentration and ultimately leads to macrocracking.Avoiding the direct and indirect generation of Al_(4)Cu_(9) is the primary means of solving the problem of cracking.The microhardness of the transition layer is higher than that of the matrix on both sides.The highest hardness is observed at the crack(804 HV),similar to that of A

关 键 词：激光选区熔化 功能梯度材料 显微组织演变 裂纹产生机理 显微硬度 

分 类 号：TG146[一般工业技术—材料科学与工程]