The Fe-Si mechanical alloying and its transformation are investigated to evaluate whether mechanical alloying is a useful process for producing Fe-Si alloy. The mechanical alloying process of Fe-Si powders is studied by SEM（ scanning electron microscopy）, EDS（energy dispersive spectrometer）and XRD（X-ray diffraction）. The results show that the ball milling process first makes tough Fe powder a lump structure and brittle Si powder a small particle, and then as the mill power increases, the tough powder of iron with a lamellar structure forms and the Si particles lies on or between the Fe lamellas. Finally, the Fe and Si powders are mechanically alloyed through atom diffusion. So the Fe and Si powders can be alloyed by 15 h ball milling at a speed of 400 r/min and with a ball-to-powder ratio of 40 ： 1. After heating at 1 243 K for 1 h, the milled powders transform to α-FeSi2, and after heating at 1 243 K for 1 h, then cooling to 1 073 K for 1 h, the milled powders transform to β-FeSi2. Therefore, the monophase α-FeSi2 or β-FeSi2 can be obtained by heat treatment of mechanically alloyed Fe-Si powders.
树脂传递模塑(resin transfer molding,RTM)工艺作为一种低成本、高尺寸精度的复合材料制备工艺,经过近两个世纪的发展已成为新型成型工艺技术的主流工艺。随着高新复合材料对力学强度、整体结构性、功能性越来越高的要求,传统RTM工艺也为迎合这些工业需求而不断发展改进。主要总结回顾了RTM工艺近些年的研究进展,并对衍生出的高压树脂传递模塑法(HIPRTM)、硅橡胶气囊辅助注入法(bladder-assisted RTM)、Seemann复合材料树脂渗透模塑法(SCRIMP)以及共注射树脂传递模塑法(CIRTM)的优缺点与应用前景进行介绍分析。
