强流脉冲电子束作用下TC4钛合金表面Cr合金层制备及性能

Preparation and property of Cr alloying layer on TC4 after surface alloying induced by high current pulsed electron beam

利用强流脉冲电子束技术(HCPEB)对TC4钛合金表面进行Cr合金化处理,从而改善了材料的表面性能。采用X射线衍射(XRD)、金相显微镜(OM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析表层中的相组成和微观结构。试验结果表明:经HCPEB表面合金化后基体表面形成了数微米的Cr合金层,合金层中析出了颗粒细小、均匀分布的Laves相Cr2Ti;同时,TC4钛合金经HCPEB轰击后表层发生了马氏体相变,形成了大量的板条马氏体组织。此外,硬度测试和电化学结果表明:经HCPEB处理后样品的表面显微硬度和耐蚀性能均得到明显提高。

To improve the surface properties of the TC4 titanium alloy,Cr alloying layers are formed on the TC4 samples′surfaces using high-current pulsed electron beam(HCPEB).The microstructure and phase analysis of the surface alloying layer were studied by X-ray diffraction(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The experimental results demonstrate that after HCPEB alloying,Cr alloyed layer about 1.5μm in thickness is formed on the surface.The diffusion of Cr element occurred on the surface of the substrate,the Ti atoms combined with the chromium to form tiny Laves phase Cr2Ti.Martensitic transformation occurred in the irradiated layer and a large number of lath martensite structures were observed in the irradiated surface.Moreover,both the surface microhardness and corrosion resistance of the HCPEB treated samples were obviously improved.