低碳钢表面Cr合金层的低温高能球磨制备

Preparation of Cr coating on low carbon steel by high-energy ball willing

采用高能球磨机,利用机械合金化原理,在室温下于20钢表面制得 Cr 合金层。采用 SEM、EDS、XRD 和显微硬度测试等技术分析 Cr 层的显微形貌、组织结构及力学性能并初步探讨合金层的形成机理。结果表明。采用本实验工艺能在20钢表面形成界面结合良好且厚度为60～80μm的 Cr 合金层。显微硬度测试表明,合金层最大显微硬度值高达661HV0.1,是基体硬度值的3倍多。界面处的显微硬度呈现梯度变化,对合金层起到很好的缓冲和支撑作用。分析其机理可知,大量机械能的输入促进了粉末与基体的结合,加快了原子间的扩散,使得 Cr 合金层得以形成。

Cr coating layer was obtained on low carbon steel substrate with ball milling machine. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDS） and micro-hardness test technique were used to investigate the microstructure and mechanical properties of the coating layer,then the formation mechanism of coating layer was discussed. The results show that a well combined and thick coating layer has been formed. The maximum hardness of the coating layer is up to 661HV0.1, which is more than three times of the substrate. Micro-hardness of the interface decreases stepwise, which does buffering effect to the coating layer. The abundant input mechanical energy promotes combination between powder and vessel, accelerates diffusion of atoms, consequently forms Cr coating layer.