Al含量对铸态Ni-20Cr-xAl-1Si合金组织和性能的影响  

Effects of Al Content on Microstructure and Properties of As-cast Ni-20Cr-xAl-1Si Alloys

作　　者：张秀发 夏天东[1,2] 王晓军[1,2] 雷智刚 ZHANG Xiufa;XIA Tiandong;WANG Xiaojun;LEI Zhigang(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050;School of Materials Science and Engineering,Lanzhou University of Technol-ogy,Lanzhou 730050)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《特种铸造及有色合金》2024年第10期1402-1408,共7页Special Casting & Nonferrous Alloys

摘　　要：采用真空电弧熔炼工艺制备了Ni-20Cr及改性的Ni-20Cr-xAl-1Si(x=3,4,5,6,7,质量分数,%)合金,采用X射线检测(XRD)、扫描电镜(SEM)、电子探针(EPMA)、拉伸测试和硬度测试等手段研究了Al含量对合金电阻率、显微组织和力学性能的影响。结果表明,Ni-20Cr合金由γ单相组成,Ni-20Cr-xAl-1Si由γ基体相和γ′-Ni_(3)Al沉淀相组成。随着Al含量增加,起沉淀强化作用并对合金电阻率提升起主要作用的γ′-Ni_(3)Al相的含量先上升后下降,固溶于γ/γ′相中起固溶强化作用的Al逐渐增多,合金电阻率先上升后下降,强度、硬度逐渐上升,塑性、韧性逐渐下降。Ni-20Cr-5Al-1Si合金的电阻率达1.523μΩ·m,较Ni-20Cr合金提升了43.81%,屈服强度、抗拉强度、硬度(HV_(0.2))分别上升至664.9MPa和864.6MPa和340.8,伸长率下降至31.83%。Ni-20Cr and modified Ni-20Cr-xAl-1Si(x=3,4,5,6,7,mass fraction,%)alloys were prepared by vacuum arc melting,and effects of Al content on resistivity,phase,microstructure and mechanical properties of NiCrAlSi alloy were investigated by XRD,SEM,EPMA,tensile and hardness tests.The results indicate that Ni-20Cr is composed ofγsingle phase,and Ni-20Cr-xAl-1Si is composed ofγmatrix phase andγ'-Ni_(3)Al precipitation phase.With the increase of Al content,the content ofγ'-Ni_(3)Al phase is firstly increased and then decreased,which plays an important role in precipitation strengthening and resistivity enhancement,and the solid solution strengthening of Al inγ/γ'phase is gradually increased,leading to the first increase and then reduction of resistivity,gradually increase in the strength and hardness,and gradually decrease in the plasticity and toughness.The resistivity of Ni-20Cr-5Al-1Si alloy reaches 1.523μΩ·m,which is increased by 43.81%compared with Ni-20Cr.The yield strength,tensile strength and hardness of the alloy are increased to 664.9 MPa,864.6 MPa and 340.8 HV_(0.2),respectively,while the elongation is decreased to 31.83%.

关 键 词：AL元素 γ′-Ni_(3)Al 电阻率 组织 力学性能 

分 类 号：TG146.15[一般工业技术—材料科学与工程]