(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 北京科技大学 新材料技术研究院，北京 100083；
3. 北京科技大学 材料先进制备技术教育部重点实验室，北京 100083)
摘 要: 通过添加其他合金元素部分取代Be，是低成本高性能铍铜合金的研究热点之一。研究了0~0.2% Al(质量分数)对Cu-0.3Be-2.0Ni合金组织和性能的影响规律及其作用机理。结果表明，随着Al含量的增加，铸造试样的晶粒尺寸逐渐减小、析出相含量逐渐增大，当Al含量为0.1%和0.15%(质量分数)时，形成晶内针状Ni3Al析出相，主要集中分布在树枝晶间区域；当Al含量增加到0.2%(质量分数)时，在晶内析出大量针状析出相的同时，在晶界形成呈链状分布的棒状Ni3Al析出相。添加Al元素提高了试样的弹性模量，Al含量由0增加至0.2%(质量分数)，试样的弹性模量从115 GPa提高到127 GPa，提高了10%，Al与Ni形成的具有高弹性模量的Ni3Al相是合金弹性模量提高的主要原因。常规时效后含0.2%Al(质量分数)的Cu-0.3Be-2.0Ni合金峰值硬度和导电率分别为238HV和44%IACS；与不加Al的合金硬度(225HV)相比，硬度提高了6%，抗过时效能力有所提高，导电率下降了6%IACS。
关键字: 铍铜合金；Al合金化；显微组织；固溶时效；弹性模量
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China;
3. Key Laboratory for Advanced Materials Processing, Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Adding other alloying elements for partial replacement of beryllium is one of the research hotspots of low-cost and high-performance beryllium copper. The effects of 0-0.2% Al content on the microstructure and properties of Cu-0.3Be-2.0Ni alloy and its mechanism were studied. The results show that, as the Al content increasing, the grain size of the cast sample decreases and the number of precipitated phase increases. When the Al contents are 0.1% and 0.15%, the needle-like Ni3Al phase precipitates inside the grains, which is mainly distributed in the interdendritic area. When the Al content increases to 0.2%, a large number of needle-like phases form inside grains, and a rod-shaped Ni3Al phase with a chain distribution forms at grain boundaries. Addition of Al improves the elastic modulus of the alloy. When the Al content increases from 0 to 0.2%, the elastic modulus increases from 115 GPa to 127 GPa, increased by 10%. The Ni3Al phase formed by Al and Ni with high elastic modulus is the main reason for the increase of elastic modulus. The peak hardness and electrical conductivity of Cu-0.3Be-2.0 Ni alloy containing 0.2% Al after conventional aging are 238HV and 44%IACS, respectively, whose hardness is increased by 6%, the overaging resistance is improved and the electrical conductivity is decreased by 6%IACS comparing with the alloy without Al.
Key words: beryllium copper alloy; aluminium alloying; microstructure; solid solution aging; elastic modulus
