Al-Si-Cu-Ni合金梯度结构对弯曲性能的影响  

Effect of gradient structure of Al-Si-Cu-Ni alloy on bending properties

作　　者：史志朝 严彪[1,2,3] 严鹏飞 SHI Zhichao;YAN Biao;YAN Pengfei(School of Materials Science and Engineering,Tongji University,Shanghai 201804,China;Suzhou Kailei Intelligent Equipment Co.,Suzhou 215332,China;Shanghai key Laboratory for D&A of Metal functional Materials,Shanghai 201804,China;Eighth Research Institute of Nuclear Industry,Shanghai 201800,China)

机构地区：[1]同济大学材料科学与工程学院,上海201804 [2]苏州开雷智能装备有限公司,江苏苏州215332 [3]上海市金属功能材料开发应用重点实验室,上海201804 [4]核工业第八研究所,上海201800

出　　处：《粉末冶金工业》2024年第3期40-45,53,共7页Powder Metallurgy Industry

摘　　要：通过改变选择性激光熔化成形过程中的激光功率,在不同工艺参数下制备了Al-Si-Cu-Ni梯度结构合金,测试了正压和反压条件下的弯曲性能。优化工艺参数后,提高了梯度结构合金的综合力学性能,观察其侧面不同位置处的微观组织结构,并测试了硬度分布。结果表明,在正压条件下的弯曲性能优于反压。随着激光功率的增大,显微组织逐渐粗化,富Cu、Ni第二相的析出数量增多,维氏硬度和布氏硬度线性降低,使得合金样品产生梯度结构。最佳工艺参数下制备的梯度结构合金在正压条件下的弯曲强度和断裂位移可达(838±22)MPa和(0.93±0.04)mm,显著高于均质结构合金((767±24)MPa、(0.85±0.03)mm),表明梯度结构对合金材料产生了强韧化作用,主要归因于细晶组织强度高,粗晶组织塑性好,二者的协同作用促进了合金的高强度和高韧性。Al-Si-Cu-Ni gradient-structured alloys were prepared under different process parameters by varying the laser power during selective laser melting and forming,and the bending properties were tested under positive and negative pressure conditions.After optimizing the process parameters,the comprehensive mechanical proper-ties of the gradient-structured alloys were improved,the microstructures at different locations on the sides were observed,and the hardness distribution was tested.The results show that the bending properties under positive pressure conditions are better than those under counterpressure.With the increase of laser power,the microstruc-ture is gradually coarsened,the precipitation amount of Cu-rich and Ni second phases increases,and the Vickers hardness and Brinell hardness linearly decrease,which makes the alloy samples produce a gradient structure.The bending strength and fracture displacement of the gradient-structured alloys prepared under the optimal process parameters under positive pressure can reach(838±22)MPa and(0.93±0.04)mm,which are significantly higher than those of the homogeneous structure alloys(767±24)MPa,(0.85±0.03)mm,indicating that the gradient structure produces a toughening effect on the alloy materials,which is mainly attributed to the high strength of the fine-crystalline tissues,good plasticity of the coarse-crystalline tissues,and good plasticity of the coarse-crys-talline tissues.The synergistic effect of the gradient structure on the alloys is mainly attributed to the high strength of the fine-crystalline tissue and the good plasticity of the coarse-crystalline tissue.

关 键 词：选择性激光熔化 Al-Si-Cu-Ni合金 梯度结构 弯曲性能 微观组织结构 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.21[一般工业技术—材料科学与工程]