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利用强流脉冲电子束进行AZ91铸造镁合金表面辐照改性,处理参数包括加速电压27 k V,脉冲次数1到30次。使用金相显微镜、扫描和透射电子显微镜观察样品表层形貌和显微组织。研究表明,原始铸造组织的粗大树枝晶α-Mg和颗粒相β-Mg17Al12发生熔解,表面成分均匀化,并形成细小的复合纳米网状结构。改性AZ91镁合金的表面显微硬度和耐磨损性能得到显著提高,8次脉冲处理样品的表面显微硬度由原始62.7 HK提高到119.4 HK,磨损速率由0.01126降至0.00173mm3/min。
The surface of AZ91 cast magnesium alloy was irradiated by intense pulsed electron beam. The processing parameters include acceleration voltage of 27 kV and pulse times of 1 to 30 times. The surface topography and microstructure of the samples were observed by scanning electron microscopy and transmission electron microscopy. The results show that the coarse dendrites α-Mg and β-Mg17Al12 in the original casting structure melt and the surface components are homogenized, and the fine composite nanomesh structure is formed. The surface microhardness and wear resistance of the modified AZ91 magnesium alloy were significantly improved. The surface microhardness of the eight pulse treatment samples increased from 62.7 HK to 119.4 HK, and the wear rate decreased from 0.01126 to 0.00173 mm3 / min.