Microstructure and Toughness Characteristic of Mo in NiAl-Fe Intermetallic Alloy

• Main Authors: HE,Chun-min, 何俊旻
• Other Authors: 蔡顯榮
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/38210245684451103170

碩士 === 國立臺灣科技大學 === 機械工程系 === 91 === The purpose of this investigation is to study the effect of Mo on the microstructure and toughness characteristic of NiAl-Fe-based alloys. The alloys used in this investigation were prepared using NiAl, Fe and Mo powders by CO2 laser melting. The microstructural evolution of these alloys was examined by optical microscopy, scanning electron microscopy, X-ray diffraction. The composition of these alloys was examined by electronic probe micro-analysis (EPMA). The mechanical property measurements by means of hardness. The toughness characteristic of these alloys was examined by crack’s lengths measuring and crack’s images observing. The results, the secondary arm spacing of NiAl-rich dendritic decreased with addition of Mo. The fine NiAl-rich and Mo-rich eutectic structure existed with addition of Mo. The microhardness of NiAl-Fe intermetallic alloys increased with Mo. The addition of 2.5at.% Mo in NiAl-Fe intermetallic alloy provided significant improvement in fracture toughness, duo to crack deflection, crack branching and local plasticity deformation.