In the present study Ti-Nb binary alloy system was chosen because it has excellent biocompatibility as well as reasonable mechanical properties,aiming at understanding oxygen content on microstructural formation, elas...In the present study Ti-Nb binary alloy system was chosen because it has excellent biocompatibility as well as reasonable mechanical properties,aiming at understanding oxygen content on microstructural formation, elastic modulus and tensile properties in Ti-Nb alloy system.Small alloy buttons of 50 mm in diameter were prepared by arc melting on a water-cooled copper hearth under an argon gas atmosphere with a non-consumable tungsten electrode.The button ingots were then heat treated in a vacuum atmosphere at 1273 K for 0.5 h followed by water quenching in a specially designed heat treatment furnace.Microstructure,elastic modulus and tensile properties were investigated in order to understand the effect of oxygen content in quenched Ti- Nb alloy system.The orthorhombic structuredα″martensite was changed to bcc structuredβ-phase with increasing Nb content.Interestingly,it was found that oxygen makesβ-phase stable in quenched Ti-Nb alloy system.Elastic modulus values were sensitive to phase stability of constituent phases.Yield strength increased with increasing oxygen content.Details will be explained by phase formation and stability behavior.展开更多
In this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microsco...In this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectroscope （EDS）. Two types of alloys were prepared by vacuum arc melting. One is Fe-28Al based alloys （D03 structured） with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys （B2 structured） produced with the same manner. For both types of alloys, Mo addition had found to exhibit an equiaxed microstructure, while dendritic structure was observed to show the effect of Zr addition. These microstructural features were more evinced with increasing content of alloying element. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys were superior to Fe-28Al based alloys over the whole temperature range investigated.展开更多
In this study, we report on advanced Ni3Al based high temperature structural alloys with Zr and B addition in order to apply in the fields of die-casting and high temperature press forming as die materials. Microstruc...In this study, we report on advanced Ni3Al based high temperature structural alloys with Zr and B addition in order to apply in the fields of die-casting and high temperature press forming as die materials. Microstructures and mechanical properties of Ni3Al based intermetallic alloys produced by vacuum arc melting were investigated in terms of phase analysis by using a scanning electron microscope （SEM） equipped with an X-ray energy dispersive spectrometer （EDS）, an X-ray diffractometer （XRD） and tensile test. The duplex microstructural feature consisting of γ＇ matrix phase and small intermetallic dispersoids was observed to be distributed over the whole microstructure. The ultimate tensile strength of the present alloy was superior to commercial iron-based and Ni-based die-materials especially in the high temperature region.展开更多
文摘In the present study Ti-Nb binary alloy system was chosen because it has excellent biocompatibility as well as reasonable mechanical properties,aiming at understanding oxygen content on microstructural formation, elastic modulus and tensile properties in Ti-Nb alloy system.Small alloy buttons of 50 mm in diameter were prepared by arc melting on a water-cooled copper hearth under an argon gas atmosphere with a non-consumable tungsten electrode.The button ingots were then heat treated in a vacuum atmosphere at 1273 K for 0.5 h followed by water quenching in a specially designed heat treatment furnace.Microstructure,elastic modulus and tensile properties were investigated in order to understand the effect of oxygen content in quenched Ti- Nb alloy system.The orthorhombic structuredα″martensite was changed to bcc structuredβ-phase with increasing Nb content.Interestingly,it was found that oxygen makesβ-phase stable in quenched Ti-Nb alloy system.Elastic modulus values were sensitive to phase stability of constituent phases.Yield strength increased with increasing oxygen content.Details will be explained by phase formation and stability behavior.
文摘In this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectroscope （EDS）. Two types of alloys were prepared by vacuum arc melting. One is Fe-28Al based alloys （D03 structured） with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys （B2 structured） produced with the same manner. For both types of alloys, Mo addition had found to exhibit an equiaxed microstructure, while dendritic structure was observed to show the effect of Zr addition. These microstructural features were more evinced with increasing content of alloying element. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys were superior to Fe-28Al based alloys over the whole temperature range investigated.
文摘In this study, we report on advanced Ni3Al based high temperature structural alloys with Zr and B addition in order to apply in the fields of die-casting and high temperature press forming as die materials. Microstructures and mechanical properties of Ni3Al based intermetallic alloys produced by vacuum arc melting were investigated in terms of phase analysis by using a scanning electron microscope （SEM） equipped with an X-ray energy dispersive spectrometer （EDS）, an X-ray diffractometer （XRD） and tensile test. The duplex microstructural feature consisting of γ＇ matrix phase and small intermetallic dispersoids was observed to be distributed over the whole microstructure. The ultimate tensile strength of the present alloy was superior to commercial iron-based and Ni-based die-materials especially in the high temperature region.
