Room temperature deformation behavior of A1-8Fe-2Mo-2V-1Zr alloy produced by spray forming and subsequent warm-extrusion at 693 K and/or rolling at 423 K was investigated in terms of tensile test and microstructural o...Room temperature deformation behavior of A1-8Fe-2Mo-2V-1Zr alloy produced by spray forming and subsequent warm-extrusion at 693 K and/or rolling at 423 K was investigated in terms of tensile test and microstructural observation.In the specimen processed by spray forming and warm extrusion, the microstructure consisting of equiaxed grains with the average grain size of 500 nm in the matrix phase and uniformly dispersed fine intermetallic A13(Fe, Mo, V, Zr) and A16(Fe, Mo, V, Zr) phases less than 100 nm was characterized. It was revealed that subsequent warm rolling after warm extrusion promotes precipitation of a fine dispersoid from the supersaturated matrix phase. Warm rolling was found to be effective to increase the yield and tensile strength in the high strain rate regime. Elongation of the warm rolled specimen showed highe r value than extruded specimen over the whole strain rate region studied.展开更多
Nd-Fe-B permanent magnets with a small amount of A1 nano-particles doping were prepared by conventional sintered method. Effect of AI content on magnetic property, corrosion resistance and oxidation properties of the ...Nd-Fe-B permanent magnets with a small amount of A1 nano-particles doping were prepared by conventional sintered method. Effect of AI content on magnetic property, corrosion resistance and oxidation properties of the magnets were studied. Inves- tigation showed that the coercivity rose gradually, while the remanence decreased simultaneously with increase of A1 doping amount. Further investigation revealed that most A1 element diffused into the main phase and some A1 element diffused into the Nd-rich phase The autoclave test results showed that the corrosion rate of the magnets decreased with A1 content increasing. After oxidation, the maximum energy product losses of the magnets with 0.0 wt.% and 0.2 wt.% AI nano-particles doping were 6.13% and 3.99%, respec- tively. Therefore, A1 nano-particles doping was a promising way to enhance the coercivity and corrosion resistance of sintered Nd-Fe-B magnet.展开更多
The influence of 0.01% to 0. 25% of Aluminum content （in mass percent） on the mechanical properties and cold workability of low thermal expansion Fe-33Ni-15Co sheets in the annealed and hot rolled condition was inve...The influence of 0.01% to 0. 25% of Aluminum content （in mass percent） on the mechanical properties and cold workability of low thermal expansion Fe-33Ni-15Co sheets in the annealed and hot rolled condition was investigated. Addition of Al up to 0.15 % resulted in the increase of ductility and tougianess and improvement of workability. Besides, achievement of fine grain structure and increase in the amount of annealing twins caused ductility to improve. Addition of Al higher than 0.15 % led to the increase in oxidation reaction during melting process and to refine under argon atmosphere. This caused the volume fraction of Al containing inclusions to increase and consequently the ductility and toughness to decrease.展开更多
文摘Room temperature deformation behavior of A1-8Fe-2Mo-2V-1Zr alloy produced by spray forming and subsequent warm-extrusion at 693 K and/or rolling at 423 K was investigated in terms of tensile test and microstructural observation.In the specimen processed by spray forming and warm extrusion, the microstructure consisting of equiaxed grains with the average grain size of 500 nm in the matrix phase and uniformly dispersed fine intermetallic A13(Fe, Mo, V, Zr) and A16(Fe, Mo, V, Zr) phases less than 100 nm was characterized. It was revealed that subsequent warm rolling after warm extrusion promotes precipitation of a fine dispersoid from the supersaturated matrix phase. Warm rolling was found to be effective to increase the yield and tensile strength in the high strain rate regime. Elongation of the warm rolled specimen showed highe r value than extruded specimen over the whole strain rate region studied.
基金Project supported by National Natural Science Foundation of China(51001002)Research Fund for the Doctoral Program of Higher Education of China(20091103120024)+3 种基金National High Technology Research and Development Program of China(2012AA063201)the Key Program of Science and Technology Development Project of Beijing Municipal Education Commission(KZ201110005007)the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions211 Project of Beijing University of Technology and Rixin Talents of Beijing Universityof Technology for financial support
文摘Nd-Fe-B permanent magnets with a small amount of A1 nano-particles doping were prepared by conventional sintered method. Effect of AI content on magnetic property, corrosion resistance and oxidation properties of the magnets were studied. Inves- tigation showed that the coercivity rose gradually, while the remanence decreased simultaneously with increase of A1 doping amount. Further investigation revealed that most A1 element diffused into the main phase and some A1 element diffused into the Nd-rich phase The autoclave test results showed that the corrosion rate of the magnets decreased with A1 content increasing. After oxidation, the maximum energy product losses of the magnets with 0.0 wt.% and 0.2 wt.% AI nano-particles doping were 6.13% and 3.99%, respec- tively. Therefore, A1 nano-particles doping was a promising way to enhance the coercivity and corrosion resistance of sintered Nd-Fe-B magnet.
文摘The influence of 0.01% to 0. 25% of Aluminum content （in mass percent） on the mechanical properties and cold workability of low thermal expansion Fe-33Ni-15Co sheets in the annealed and hot rolled condition was investigated. Addition of Al up to 0.15 % resulted in the increase of ductility and tougianess and improvement of workability. Besides, achievement of fine grain structure and increase in the amount of annealing twins caused ductility to improve. Addition of Al higher than 0.15 % led to the increase in oxidation reaction during melting process and to refine under argon atmosphere. This caused the volume fraction of Al containing inclusions to increase and consequently the ductility and toughness to decrease.
