摘要
利用EBSD方法定量统计WC晶粒圆度,探索球磨时间对合金组织结构、WC晶粒圆度及力学性能的影响规律。本研究首次明确:当球磨时间在5 h至30 h内增加时,WC晶粒和(Ta,Nb,W)C固溶体持续细化,WC晶粒平均圆度从0.71提升至0.78,其平均圆度提升9.9%;小粒径WC(D_(eq)≤0.9μm)晶粒占比是影响合金平均圆度的关键因素,其占比从球磨5 h的35.7%大幅增加至30 h的83.1%,平均圆度提升8.1%,提升幅度占合金的81.8%;随着球磨时间增加,合金的硬度、抗弯强度持续升高,而断裂韧性持续下降,疲劳性能则先升后降,高温硬度下降幅度显著增大;最优球磨时间为25 h,此时合金兼具较高硬度(1521HV)、抗弯强度(3489 N/mm^(2))与疲劳性能,且断裂韧性下降幅度可控。本研究通过揭示球磨时间对WC晶粒圆度与力学性能的调控规律,为制备综合性能优异的硬质合金提供了关键指导。
Electron backscatter diffraction(EBSD)was used to quantitatively analyze the sphericity of WC grains to investigate the influence of ball milling time on the microstructure,WC grain sphericity,and mechanical properties of the alloy.This study reveals for the first time that as the ball milling time increases from 5 h to 30 h,the WC grains and(Ta,Nb,W)C solid solution are continuously refined.The average sphericity of WC grains increases from 0.71 to 0.78,representing an improvement of 9.9%.The proportion of fine-grained WC(D_(eq)≤0.9μm)is the key factor affecting the average sphericity of the alloy.Its proportion increases significantly from 35.7%at 5 h to 83.1%at 30 h,contributing to an 8.1%increase in average sphericity,which accounts for 81.8%of the total improvement.With the increase in ball milling time,the hardness and flexural strength of the alloy increase continuously,while the fracture toughness decreases continuously.The fatigue performance increases first and then decreases,and the decrease amplitude of high-temperature hardness increases significantly.The optimal ball milling time is 25 h.At this time,the alloy possesses high hardness(1521HV),flexural strength(3489 N/mm^(2)),and fatigue performance,while the decrease in fracture toughness is controllable.By revealing the regulation mechanism of ball milling time on WC grain sphericity and mechanical properties,this study provides key guidance for the preparation of cemented carbides with excellent comprehensive properties.
作者
于涛
罗学全
陈利
瞿峻
温光华
李思敏
Yu Tao;Luo Xuequan;Chen Li;Qu Jun;Wen Guanghua;Li Simin(Zhuzhou Cemented Carbide Cutting Tools Co.,Ltd.,Zhuzhou Hunan 412007,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha Hunan 410083,China)
出处
《硬质合金》
2026年第1期18-24,43,共8页
Cemented Carbides
基金
中钨高新股份有限公司揭榜挂帅项目(20240502)。
关键词
硬质合金
球磨时间
WC晶粒圆度
力学性能
cemented carbide
ball milling time
WC grain sphericity
mechanical property
