摘要
纳米球状L1_(2)-γ′相(Pm~-3m,a=0.3572 nm)的共格析出强化Cu-Ni-Al合金兼具优异的力学性能及一定的导电性能,被广泛应用于轨道交通、海洋运输等领域。目前缺乏纳米球状L1_(2)-γ′相共格析出的Cu-Ni-Al显微组织演变及性能关联的系统研究。本文锁定Ni∶Al原子比3∶1,制备了系列Cu_(y)(Ni_(3/4)Al_(1/4))_(100-y) (y=75.00,80.00,85.71,90.00,93.75;原子分数)合金,并详细探讨了合金性能(硬度、电导率及软化温度)、合金成分及显微组织之间的关联。结果表明,低温时效后样品出现大量的退火孪晶并析出纳米球状L1_(2)-γ′相。低温时效后Cu-Ni-Al合金的强化机制包括细晶强化和析出强化,随着Cu含量增加(Ni+Al含量减少),退火孪晶含量减少且L1_(2)-γ′相的析出含量逐渐增加,合金硬度、屈服强度及极限抗拉强度也随之降低。而合金导电性能与固溶在Cu基体中的溶质含量相关。最后,通过软化温度测试衡量了合金在高温下的应用潜力。本研究为高性能Cu-Ni-Al合金成分设计提供了有效的实验及理论依据。
Nano-spherical L1_(2)-γ'phase coherent precipitation-strengthened Cu-Ni-Al alloys exhibit excellent mechanical properties and certain electrical conductivity,enabling them widely used in the fields of rail transportation and marine transportation.However,there is currently a lack of systematic studies on the relationship between the microstructural evolution and performance.In this study,the Cu_(y)(Ni_(3/4)Al1/4)_(100-y)(y=75.00,80.00,85.71,90.00,93.75)alloys with the fixed Ni∶Al atomic ratio of 3∶1 were prepared,and the con-nection between the properties(hardness,electrical conductivity,and softening temperature)of and their composition and microstruc-ture was investigated.The results showed that there existed a large amount of annealing twinning and nano-spherical L1_(2)-γ'phases in the microstructure of the alloys after low-temperature aging treatment.The strengthening mechanism of Cu-Ni-Al alloys included both grain refinement strengthening and precipitation strengthening.With the increase of Cu content(decrease of Ni+Al content),the con-tent of annealing twinning and the precipitation content of L1_(2)-γ'phase decreased.Consequently,the hardness,yield strength,and ulti-mate tensile strength of the alloys decreased.The electrical conductivity of the alloy was correlated with the content of solutes dissolved in Cu matrix.Finally,the potential of the alloy for high-temperature applications was evaluated through softening temperature tests.This study provided an effective experimental and theoretical basis for the composition design of high-performance Cu-Ni-Al alloys.
作者
薛汪洋
刘桐
胡小刚
利助民
XUE Wangyang;LIU Tong;HU Xiaogang;LI Zhumin(School of Materials Science and Engineering,Anhui Polytechnic University,Wuhu 241000,China;Xi'an Research Institute of Rare Metal Materials Co.,Ltd.,Xi'an 710000,China)
出处
《铜业工程》
CAS
2023年第5期70-78,共9页
Copper Engineering
基金
高性能有色金属材料安徽省重点实验室开放课题(YSJS-2023-08)
安徽工程大学引进人才科研启动基金项目(2200YQQ048)资助。
