不同振荡热压烧结温度下90W-10Cu难熔合金组织及性能  

Microstructures and Properties of 90W-10Cu Refractory Alloy Sintered Under Different Hot Oscillatory Pressure Sintering Temperature

作　　者：高卡 赵桅 孙德建 高阳 朱文博[1] GAO Ka;ZHAO Wei;SUN Dejian;GAO Yang;ZHU Wenbo(School of Mechanical Eng.,Univ.of Shanghai for Sci.and Technol.,Shanghai 200093,China;General Practice Dept.,Changhai Hospital,Shanghai 200433,China;School of Materials,Zhengzhou Univ.of Aeronautics,Zhengzhou 450015,China)

机构地区：[1]上海理工大学机械工程学院,上海200093 [2]长海医院全科医学科,上海200433 [3]郑州航空工业管理学院材料学院,河南郑州450015

出　　处：《工程科学与技术》2024年第3期269-276,共8页Advanced Engineering Sciences

基　　金：国家自然科学基金资助项目(51904277,52374370);河南省高等学校青年骨干教师计划项目(2020GGJS171)。

摘　　要：用于高压电触头材料的90W-10Cu难熔合金由于具有高熔点和高比重差异,在高温长时间的粉末冶金过程中存在致密化困难和晶粒异常长大而影响其性能。在常规热压烧结基础上,振荡热压烧结(HOP)技术采用一定频率的循环振荡单轴压力代替静单轴压力,可快速促进陶瓷等材料的致密化。因此,为了研究振荡热压烧结对90W-10Cu难熔合金的低温烧结效果,本文将振荡热压烧结技术应用到90W-10Cu(质量分数)难熔合金的制备中,研究了烧结温度(1000~1300℃)对其微观组织、致密度、晶粒尺寸、硬度及电导率性能的影响。研究结果发现,振荡热压烧结90W-10Cu合金由W相基体和Cu相黏结相组成。随着烧结温度的升高,90W-10Cu难熔合金的致密度逐渐增大,在烧结温度最高为1300℃时,其致密度最高可达到99.35%,均高于同等温度下的热压烧结样品的致密度;而晶粒尺寸仅为4.97μm左右,没有异常长大,达到了细化晶粒的效果;同时,其W晶粒邻接度逐渐降低,合金的微观组织均匀性得到优化和改善;维氏硬度和电导率分别达到225.78 HV_(30)和27.88%国际退火铜标准(IACS),高于同等温度甚至高100℃时的热压烧结体,性能得到显著提升,达到了低温烧结效果。结果表明,振荡热压烧结能够有效地促进90W-10Cu难熔合金的致密化,降低烧结温度和抑制晶粒生长,显著优化其微观组织均匀性,有利于在较低温度下获得高致密度、晶粒细小、高硬度和高电导率的90W-10Cu难熔合金材料。Due to the differences in high melting point and specific gravity,the 90W-10Cu refractory alloy,used in high-voltage electrical con-tact materials,experiences challenges in densification and abnormal grain growth during the high-temperature,long-duration powder metallurgy process,affecting its properties.Based on conventional hot press sintering,the novel hot oscillatory pressure(HOP)technology enhances the densification of ceramics and other materials by substituting static uniaxial pressure with cyclic oscillatory uniaxial pressure at a specific fre-quency.In order to investigate the low-temperature sintering effects of HOP on the 90W-10Cu refractory alloy,this technology is applied to the alloy’s preparation,examining the impacts of varying sintering temperatures(1000~1300°C)on its microstructure,densification,grain size,hardness,and electrical conductivity.The 90W-10Cu alloy comprises a W matrix phase and a bonding Cu phase.As the sintering temperature in-creases,the W-Cu alloy’s density gradually rises,reaching a peak density of nearly 99.35%at 1300°C,surpassing that of samples sintered under hot pressure(HP).The grain size is reduced to 4.97μm,affecting grain refinement.Simultaneously,W grain contiguity decreases,enhancing mi-crostructure uniformity.Consequently,its Vickers hardness and electrical conductivity reached 225.78 HV_(30) and 27.88%IACS,respectively,ex-ceeding those of HP-sintered samples at the same temperature of+100°C,thus considerably enhancing its properties.The findings indicated that HOP effectively promotes the densification of the W-Cu alloy at lower sintering temperatures,inhibits grain growth,and significantly optimizes microstructure uniformity.Therefore,the 90W-10Cu alloy for electrical contacts,characterized by high density,fine grain,and improved hard-ness and conductivity,can be achieved through HOP at low-temperature sintering.

关 键 词：烧结 难熔合金 致密化 晶粒尺寸及形貌 硬度 电导率 

分 类 号：TB3[一般工业技术—材料科学与工程]