Kim JaeHwang, Kim DaeHwan
Carbon and Light Materials Application Group, Korea Institute of Industrial Technology, Jeonju-si, Jeollabuk-do, 54853, South Korea.
Division of Advanced Materials Engineering, Chonbuk National University, Jeonju-si, Jeollabuk-do, 54896, South Korea.
J Nanosci Nanotechnol. 2018 Mar 1;18(3):2137-2139. doi: 10.1166/jnn.2018.14980.
Fe is intentionally added in order to form the Fe intermetallic compounds (Fe-IMCs) during casting. Field emission scanning electron microscope with energy dispersive spectrometer (EDS) was conducted to understand microstructural changes and chemical composition analyses. The needlelike Fe-IMCs based on two dimensional observation with hundreds of micro size are modified to fragmented particles with the minimum size of 300 nm through clod rolling with 80% thickness reduction. The ratio of Fe:Si on the fragmented Fe-IMCs after 80% reduction is close to 1:1, representing the β-Al5FeSi. The yield and tensile strengths are increased with increasing reduction rate. On the other hand, the elongation is decreased with the 40% reduction, but slightly increased with the 60% reduction. The elongation is dramatically increased over two times for the specimen of 80% reduction compared with that of the as-cast. Fracture behavior is strongly affected by the morphology and size of Fe-IMCs. The fracture mode is changed from brittle to ductile with the microstructure modification of Fe-IMCs.
在铸造过程中有意添加铁以形成铁金属间化合物（Fe-IMCs）。利用带有能量色散谱仪（EDS）的场发射扫描电子显微镜来了解微观结构变化并进行化学成分分析。基于二维观察的数百个微米尺寸的针状Fe-IMCs通过80%厚度减薄的冷轧被改造成最小尺寸为300纳米的破碎颗粒。80%减薄后破碎的Fe-IMCs上的Fe:Si比接近1:1，代表β-Al5FeSi。屈服强度和抗拉强度随着减薄率的增加而提高。另一方面，伸长率在40%减薄时降低，但在60%减薄时略有增加。与铸态相比，80%减薄试样的伸长率显著增加了两倍多。断裂行为受到Fe-IMCs的形态和尺寸的强烈影响。随着Fe-IMCs微观结构的改变，断裂模式从脆性变为韧性。
