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利用强流脉冲电子束(HCPEB)进行YG10硬质合金表面辐照处理。通过金相显微镜、扫描电镜和X射线衍射方法分析表层显微组织演变,并测量样品表面显微硬度和磨损性能变化规律。分析表明,HCPEB辐照引发YG10样品表层快速熔凝,原始微米尺寸的WC晶粒转变为纳米细化组织,Co粘结相消失,表面产生网状微裂纹,改性层(厚度约1.5μm)中的WC逐步转化为WC_(1-x)相,同时伴随纳米碳粒子、W_2C相的析出和重新分布过程。样品表面显微硬度随脉冲次数增加呈线性提高,由原始的1735.8 Hv增加到35次脉冲的3128.5 Hv。6次脉冲处理样品的耐磨性能最佳,磨损率降为原始样品的40%,表层纳米细化组织和弥散碳粒子析出是耐磨性能改善的主要原因。
High intensity pulsed electron beam (HCPEB) was used to irradiate YG10 cemented carbide surface. The microstructure evolution of the surface layer was analyzed by metallographic microscope, scanning electron microscopy and X-ray diffraction. The variation of microhardness and wear resistance on the sample surface was measured. The results showed that the surface layer of YG10 sample was rapidly melted by HCPEB irradiation, the original microscopic WC grains were transformed into the nanostructured microstructure, the Co binder phase disappeared, and the reticular microcracks were formed on the surface. The modified layer (about 1.5μm in thickness) WC gradually transformed into WC_ (1-x) phase, accompanied by precipitation and redistribution of carbon nanocarbons and W_2C phases. The microhardness increases linearly with the increase of pulse number from the original 1735.8 Hv to 358 pulses of 3128.5 Hv. The wear resistance of 6 samples was the best, and the wear rate was reduced to 40% of the original sample. The precipitation of superfine nanostructured microstructure and dispersed carbon particles was the main reason for the improvement of wear resistance.