利用高能喷丸(high energy shot peening,HESP)法在电工纯铁表面获得了一定厚度的纳米晶层;同时采用在喷丸弹丸中添加镍粉和铬粉的方法,实现了电工纯铁表面自纳米化-合金化改性。运用金相显微镜、扫描电镜、X射线衍射分析以及电化学测...利用高能喷丸(high energy shot peening,HESP)法在电工纯铁表面获得了一定厚度的纳米晶层;同时采用在喷丸弹丸中添加镍粉和铬粉的方法,实现了电工纯铁表面自纳米化-合金化改性。运用金相显微镜、扫描电镜、X射线衍射分析以及电化学测试系统等手段对自纳米化层以及合金化层的组织结构进行了表征,重点对其耐蚀性进行了测试分析。结果表明,采用HESP方法,在0.6MPa喷丸压力下喷丸6min,即可在电工纯铁表面形成一定厚度晶粒大小为47.9nm、微观畸变为0.0431%的纳米晶层。由于表面自纳米化层中晶界数量急剧增加,变形产生的大量缺陷使电工纯铁表面具有较高的储存能,导致表面原子的活性提高,耐蚀性降低。而渗Ni合金化后试样的腐蚀电位Ecorr=-0.535V,渗Cr合金化后试样的腐蚀电位Ecorr=-0.459V,均大于原始试样的腐蚀电位,经过合金化改性以后,电工纯铁的耐蚀性有所提高。展开更多
Surface nanocrystallization of pure Fe was performed using an improved surface treatment process. The phase transformation and Si infiltration depth of the pure Fe before and after surface mechanical attrition treatme...Surface nanocrystallization of pure Fe was performed using an improved surface treatment process. The phase transformation and Si infiltration depth of the pure Fe before and after surface mechanical attrition treatment （SMAT） were compared by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicated that nanocrystallization of Fe surface was achieved using SMAT, which resulted in deeper penetration of Si. Prolonging time of SMAT and Si infiltration also resulted in increasing microhardness, with the hardness first increasing with increasing distance from the surface and then decreasing. Furthermore, longer Si infiltration time, nanocrystallization of Si and longer SMAT time resulted in higher saturation magnetization （MS）. The greatest Si penetration depth （150 μm）, maximum hardness （280 HV）, and maximum MS （1.849 × 10^6 A/m） were achieved after SMAT for 45 min and Si infiltration for 9 h. The interaction between adjacent grains after surface nanocrystallization leads to a region of the magnetic domain wall structure located at the grain boundary, which causes the remanence enhancement effect.展开更多
文摘利用高能喷丸(high energy shot peening,HESP)法在电工纯铁表面获得了一定厚度的纳米晶层;同时采用在喷丸弹丸中添加镍粉和铬粉的方法,实现了电工纯铁表面自纳米化-合金化改性。运用金相显微镜、扫描电镜、X射线衍射分析以及电化学测试系统等手段对自纳米化层以及合金化层的组织结构进行了表征,重点对其耐蚀性进行了测试分析。结果表明,采用HESP方法,在0.6MPa喷丸压力下喷丸6min,即可在电工纯铁表面形成一定厚度晶粒大小为47.9nm、微观畸变为0.0431%的纳米晶层。由于表面自纳米化层中晶界数量急剧增加,变形产生的大量缺陷使电工纯铁表面具有较高的储存能,导致表面原子的活性提高,耐蚀性降低。而渗Ni合金化后试样的腐蚀电位Ecorr=-0.535V,渗Cr合金化后试样的腐蚀电位Ecorr=-0.459V,均大于原始试样的腐蚀电位,经过合金化改性以后,电工纯铁的耐蚀性有所提高。
文摘Surface nanocrystallization of pure Fe was performed using an improved surface treatment process. The phase transformation and Si infiltration depth of the pure Fe before and after surface mechanical attrition treatment （SMAT） were compared by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicated that nanocrystallization of Fe surface was achieved using SMAT, which resulted in deeper penetration of Si. Prolonging time of SMAT and Si infiltration also resulted in increasing microhardness, with the hardness first increasing with increasing distance from the surface and then decreasing. Furthermore, longer Si infiltration time, nanocrystallization of Si and longer SMAT time resulted in higher saturation magnetization （MS）. The greatest Si penetration depth （150 μm）, maximum hardness （280 HV）, and maximum MS （1.849 × 10^6 A/m） were achieved after SMAT for 45 min and Si infiltration for 9 h. The interaction between adjacent grains after surface nanocrystallization leads to a region of the magnetic domain wall structure located at the grain boundary, which causes the remanence enhancement effect.
