强流脉冲电子束辐照WC-Ni硬质合金表面改性  

Modification of WC-Ni hard alloy irradiated by intense pulsed electron beam

作　　者：张锋刚[1] 董洪峰[1] 王楠[2] 朱小鹏[3] 雷明凯[3] 

机构地区：[1]陕西理工大学材料科学与工程学院,陕西汉中723001 [2]陕西理工大学机械工程学院,陕西汉中723001 [3]大连理工大学材料科学与工程学院,辽宁大连116024

出　　处：《金属热处理》2017年第9期172-177,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(51605269);陕西省自然科学基础研究计划项目(2015JQ5193);陕西理工学院科研基金(SLGQD14-12)

摘　　要：利用电子能量为127 keV、能量密度为34 J/cm^2、脉冲宽度为180 ns的强流脉冲电子束(IPEB)对WC-13Ni硬质合金的表面进行1~10次的辐照处理。利用XRD、SEM和EPMA等测试方法研究了IPEB辐照前后WC-Ni硬质合金表层相组成、表面形貌和元素分布的变化,借助显微硬度计和环-块式磨损仪测试了辐照前后硬质合金表层的性能。结果表明:IPEB辐照使硬质合金表面发生快速重熔和Ni粘结相择优烧蚀,导致α-WC相向β-WC_(1-x)和α-W_2C亚稳相转变;同时,辐照诱发的应力波的冲击作用使硬质合金表层深度硬化,硬化层深度可达210~380μm。IPEB辐照显著降低了硬质合金的摩擦因数和磨损率,10次辐照分别降低约32%和64%,这由于IPEB辐照硬质合金表层组织重熔细化和深层硬化。The WC-13Ni hard alloy was treated by intense pulsed electron on beam （IPEB） with electron energy of 127 keV, energy density of 34 J/cm2, and at a pulse duration of 180 ns up to 10 shots. The phase composition, surface morphology and element distribution of WC- Ni hard alloy before and after IPEB irradiation were investigated by means of XRD, SEM and EPMA, and its properties were characterized by mierohardness measurement and block-on-ring wear testing. It is found that the surface remelting and selective ablation of the nickel binder phase on the IPEB-irradiated hard alloy result in the phase transformation from hexagonal WC to cubic β-WC1-x and α-W2C in the irradiated surface layer. Hardening effect was induced on the surface layer of WC-13Ni hard alloy as a result of the strong stress wave from the IPEB irradiation, and the depth of the hardening layer increases up to 210 - 380 μm. IPEB irradiation can resuh in the reduction of the friction coefficient and wear rate of the WC-13Ni hard alloy by 32% and 64% after 10 shots of IPEB irradiation, respectively,which is due to the surface mierostrueture remelting and grain refinement, and surface layer hardening.

关 键 词：强流脉冲电子束 硬质合金 表面改性 磨损率 

分 类 号：TG135.5[一般工业技术—材料科学与工程]