YG20硬质合金强流脉冲电子束表面改性研究

发布时间：2018-05-10 07:27

本文选题：强流脉冲电子束 + YG20硬质合金　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：硬质合金在工业各个领域都有广泛应用,因其在比较恶劣的环境中服役,容易发生磨损、腐蚀及断裂等破坏。为提高硬质合金的使役性能和使用寿命,最常用的方法就是对其进行表面改性处理。实验对YG20硬质合金进行强流脉冲电子束(HCPEB)表面改性处理,在加速电压23.4kV、脉冲宽度2.5μs的条件下分别对YG20合金进行3、5、10、15、25、35次辐照处理,通过SEM、XRD、EPMA、TEM和表面粗糙度等分析测试技术来表征处理后表面微观结构发生的变化情况,通过显微硬度、耐磨性及耐蚀性测试技术来表征处理后材料表面性能的变化情况。HCPEB处理后,表面诱发形成熔坑和微裂纹形貌。相结构改变,形成纳米尺寸的新相WC1-X、Co3W3C、Co3W9C4和石墨。25次处理时,表面粗糙度、显微硬度和耐磨性性能最佳,表面粗糙度由0.521μm降至0.09μm,显微硬度从基体的1170.6HV提高至1359HV,耐磨性提高了2.11倍。10次处理时,耐蚀性能最佳,自腐蚀电流密度从基体的17.25μA/cm2降至2.433μA/cm2;25次处理后的耐蚀性是基体的3.55倍,自腐蚀电流密度值为从基体的17.25μA/cm2降至4.860μA/cm2。HCPEB可以有效改善YG20硬质合金的表面质量、显微硬度、耐磨性以及耐蚀性,其中,25次HCPEB辐照处理获得的改性效果最佳。
[Abstract]:Cemented carbides are widely used in various fields of industry, because of their service in harsh environments, they are prone to wear, corrosion and fracture. In order to improve the mechanical properties and service life of cemented carbides, surface modification is the most commonly used method. The surface of YG20 cemented carbide was modified by high current pulsed electron beam (YG20). Under the condition of accelerated voltage of 23.4kV and pulse width of 2.5 渭 s, the YG20 alloy was irradiated for three times. The changes of surface microstructure after treatment were characterized by means of SEM XRDX EPMA TEM and surface roughness analysis, and the changes of surface properties after treatment were characterized by microhardness, wear resistance and corrosion resistance. The surface induced melting pits and microcracks were formed. The surface roughness, microhardness and wear resistance of nano-sized new phase WC1-XC3W3Co3W9C4 and graphite were the best when the phase structure was changed. The surface roughness was reduced from 0.521 渭 m to 0.09 渭 m, and the microhardness was increased from 1170.6HV of the substrate to 1359HV.The wear resistance of the substrate was improved by 2.11 times .10 times, and the corrosion resistance was 3.55 times of that of the substrate after the corrosion current density was reduced from 17.25 渭 A/cm2 of the substrate to 2.433 渭 A / cm ~ (2) C _ (2), and the corrosion resistance of the substrate was increased from 0.521 渭 m to 0.09 渭 m. The surface quality, microhardness, wear resistance and corrosion resistance of YG20 cemented carbides can be effectively improved by reducing the corrosion current density from 17.25 渭 A/cm2 to 4.860 渭 A/cm2.HCPEB of the matrix. Among them, 25 times of HCPEB irradiation treatment has the best effect on the surface quality, wear resistance and corrosion resistance of YG20 cemented carbides.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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