Iron aluminides exhibit good resistance to high-temperature sulfidizing and oxidizing environments and potential for structural applications at high temperatures under corrosive environments. In this study, Fe-Al inte...Iron aluminides exhibit good resistance to high-temperature sulfidizing and oxidizing environments and potential for structural applications at high temperatures under corrosive environments. In this study, Fe-Al intermetallic compound was prepared by multi-layered roll-bonding of elemental Fe and Al foils. The process consisted of the accumulative roll-bonding (ARE) for making a laminated Fe/Al sheet and the subsequent heat treatment promoting a solid phase reaction in the laminated Fe/Al sheet. The microstructures produced at each processing stage were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness testing was used for hardness determination. A homogeneous intermetallic compound of Fe3Al or FeAl could be obtained after the subsequent heat treatment for 1.8 ks at 973 K and for 10.8 ks at 1123 or 1173 K.展开更多
In order to prepare a hypereutectic Al-Si alloy with low coefficients of thermal expansion (CTE), Al-50%Si alloy was produced by powder metallurgy (P/M) and ingot metallurgy (I/M). P/M specimen was prepared by mechani...In order to prepare a hypereutectic Al-Si alloy with low coefficients of thermal expansion (CTE), Al-50%Si alloy was produced by powder metallurgy (P/M) and ingot metallurgy (I/M). P/M specimen was prepared by mechanical alloying (MA) and pulsed electric-current sintering (PECS). The microstructures of specimens were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness and CTE measurements were performed. The grains in the P/M specimen were refined with increasing MA time. Primary Si and eutectic Si in the I/M specimen were remarkably refined by adding minute amounts of Sr. The CTE of P/M and I/M specimens were estimated as T.SxlO"6 and 10.7xlO"6, respectively. These values were as same as a CTE of AlaOs ceramics.展开更多
文摘Iron aluminides exhibit good resistance to high-temperature sulfidizing and oxidizing environments and potential for structural applications at high temperatures under corrosive environments. In this study, Fe-Al intermetallic compound was prepared by multi-layered roll-bonding of elemental Fe and Al foils. The process consisted of the accumulative roll-bonding (ARE) for making a laminated Fe/Al sheet and the subsequent heat treatment promoting a solid phase reaction in the laminated Fe/Al sheet. The microstructures produced at each processing stage were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness testing was used for hardness determination. A homogeneous intermetallic compound of Fe3Al or FeAl could be obtained after the subsequent heat treatment for 1.8 ks at 973 K and for 10.8 ks at 1123 or 1173 K.
文摘In order to prepare a hypereutectic Al-Si alloy with low coefficients of thermal expansion (CTE), Al-50%Si alloy was produced by powder metallurgy (P/M) and ingot metallurgy (I/M). P/M specimen was prepared by mechanical alloying (MA) and pulsed electric-current sintering (PECS). The microstructures of specimens were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness and CTE measurements were performed. The grains in the P/M specimen were refined with increasing MA time. Primary Si and eutectic Si in the I/M specimen were remarkably refined by adding minute amounts of Sr. The CTE of P/M and I/M specimens were estimated as T.SxlO"6 and 10.7xlO"6, respectively. These values were as same as a CTE of AlaOs ceramics.