摘要
高Sn含量的Cu-15Ni-8Sn合金在传统铸造过程中极易产生Sn宏观偏析,降低材料的力学性能。为缓解偏析程度,采用激光选区熔化(Selective laser melting,SLM)技术制备此合金,通过XRD、OM、SEM、EPMA、EBSD、TEM、激光共聚焦显微镜等方法研究了合金的显微组织、拉伸和摩擦磨损性能。结果表明:SLM快熔快凝的工艺特点能够将Sn偏析抑制在微米级别,大量的Sn固溶到基体中,同时晶粒被细化到约2.13μm;显微组织由贫Sn的α-Cu(Ni,Sn)基体和富Sn的γ-(Cu_(x)Ni_(1−x))3Sn沉淀相颗粒组成,γ颗粒直径约0.2μm。试样具有优异的强度和韧性,抗拉强度为(572.99±11.07)MPa,断裂伸长率为(12.36±1.66)%。SLM成形Cu-15Ni-8Sn合金的高强度来源于细晶强化、固溶强化、析出强化和位错强化的贡献,其摩擦因数为0.5032,磨损机制为磨粒磨损,具有较高的耐磨性能。
The Sn macro-segregation is easy to produce in the traditional casting process for Cu-15Ni-8Sn alloy with high Sn content,which reduces the mechanical properties.In order to reduce the segregation,the alloy was fabricated by selective laser melting(SLM).The microstructure,tensile and tribological properties were investigated by X-ray diffractometer(XRD),optical microscope(OM),scanning electron microscope(SEM),electron probe micro-analyzer(EPMA),electron backscatter diffraction(EBSD),field emission transmission electron microscope(TEM)and laser confocal microscope.The results indicate that Sn segregation is inhibited at the micron level due to the rapid solidification,and a large amount of Sn atoms are dissolved into the matrix.The grains are also refined to about 2.13μm.The microstructure is composed of Sn-depletedα-Cu(Ni,Sn)matrix and Sn-richγ-(Cu_(x)Ni_(1−x))3Sn precipitates.The diameter ofγparticles is about 0.2μm.The samples have excellent strength and toughness,with the ultimate tensile strength of(572.99±11.07)MPa and the elongation at break of(12.36±1.66)%.The high strength of SLM-fabricated Cu-15Ni-8Sn alloy is due to the contribution of the grain boundary strengthening,solid solution strengthening,precipitation strengthening and dislocation strengthening.The coefficient of friction is 0.5032,and abrasive wear is the dominant wear mechanism,leading to excellent wear resistance.
作者
李继康
张净凯
张振武
李伟
魏青松
LI Ji-kang;ZHANG Jing-kai;ZHANG Zhen-wu;LI Wei;WEI Qing-song(State Key Laboratory of Material Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Key Laboratory of Metallurgical Equipment and Control Technology,Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Precision Manufacturing Institute,Wuhan University of Science and Technology,Wuhan 430081,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2023年第2期386-399,共14页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51905193,51775207)
武汉市科技局技术创新项目(2020010602012037)
中央高校基本科研业务费专项资金资助项目(2021yjsCXCY028)。
