固溶和时效对铜镍铝高温合金组织及性能的影响  

Effect of solution and aging on microstructure and properties of copper-nickel-aluminum superalloy

作　　者：王自越 赵亚军 赵孟欣 程啸林 邹存磊 张爽 董闯 WANG Zi-yue;ZHAO Ya-jun;ZHAO Meng-xin;CHENG Xiao-lin;ZOU Cun-lei;ZHANG Shuang;DONG Chuang(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China;Key Laboratory of Materials Modification by Laser Ion and Electron Beams Ministry of Education,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028 [2]大连理工大学三束材料改性教育部重点实验室,辽宁大连116024

出　　处：《材料热处理学报》2025年第2期164-173,共10页Transactions of Materials and Heat Treatment

基　　金：大连市青年科技之星支持项目(2020RQ130)。

摘　　要：铜合金因其良好的导电性,且在高温下表面生成CuO自润滑层,可作为自润滑材料用于高温摩擦器件。高温合金的高温抗力来自于高稳定析出相以及共格界面对位错运动的阻碍(立方状γ′相在面心立方γ相固溶体基体上的共格析出)。据此,本课题组开发了一种新型Cu基Cu-Ni-Al高温合金,并探讨了其合适的热处理工艺,以实现对合金立方状γ′相+γ相的两相组织的调控,获得合适的两相匹配,从而提升其高温性能。采用光学显微镜和扫描电镜分析了经不同工艺热处理后合金的组织特点。结果表明:经1100℃保温4 h的固溶处理,可以有效消除铸态Cu-Ni-Al合金的枝晶,获得均匀的单相固溶体组织;冷却速度及时效温度决定了γ′相的析出状态,冷却速度越大,时效温度越低,析出相的尺寸就越小;Cu-Ni-Al合金的组织状态直接决定了合金的力学性能,随着γ′相的平均等效直径减小和体积分数增加,合金的维氏硬度增加;经1100℃保温4 h空冷至600℃保温1 h的工艺处理后,合金组织中的析出相等效直径为0.307μm,体积分数为67.6%,此时合金的力学性能最佳,抗拉强度为819.68 MPa,伸长率为2.5%。Copper alloys,due to their good conductivity and the formation of a CuO self-lubricating layer on the surface at high temperatures,can be used as a self-lubricating material for high-temperature friction devices.The high-temperature resistance of high-temperature alloys comes from their precipitated phase with high stability,as well as the impediment to dislocation motion by the coherent interfaces(coherent precipitation of cubic γ′ phase in the solid solution matrix of γ phase with FCC structure).Based on this,our research group has developed a new type of Cu based Cu-Ni-Al superalloy and explored its suitable heat treatment process to regulate the two-phase structure of the cubic γ′ phase+γ phase of the alloy,obtain appropriate two-phase matching,and thereby improve its high-temperature performance.Microstructure characteristics of the alloy after different heat treatments were analyzed using optical microscope and scanning electron microscopy.The results show that the solution treatment at 1100 ℃ for 4 h can effectively eliminate dendrites in the as-cast Cu-Ni-Al alloy and obtain a uniform single-phase solid solution structure.The cooling rate and aging temperature determine the precipitation state of γ′ phase,the higher the cooling rate,the lower the aging temperature,and the smaller the size of the precipitated phase.The microstructure of the Cu-Ni-Al alloy directly determines its mechanical properties,as the average equivalent diameter of γ′ phase decreases and the volume fraction increases,the Vickers hardness of the alloy increases.After heat treatment by holding at 1100 ℃ for 4 h and then air cooling to 600 ℃ and holding for 1 h,the precipitated phase in the alloy structure has an equivalent diameter of 0.307 μm and a volume fraction of 67.6%.At this time,the mechanical properties of the alloy are the best,with a tensile strength of 819.68 MPa and an elongation of 2.5%.

关 键 词：Cu-Ni-Al高温合金 γ′相 微观组织 热处理 

分 类 号：TG132.3[一般工业技术—材料科学与工程]