In this paper,super-thin free-standing diamond grains-nickel composite film in large area were prepared by using electrotyping method,which were used to make super-thin cutting blades.Scanning electron microscope(SEM)...In this paper,super-thin free-standing diamond grains-nickel composite film in large area were prepared by using electrotyping method,which were used to make super-thin cutting blades.Scanning electron microscope(SEM) were used to analyse the characteristics of the film.It was found that the agitation velocity and the place of impeller strongly affected the content and uniformity of diamond grains in deposited composite film when the other parameters were the same.The best film was deposited when agitation velocity was 180-220 r/m and the impeller was placed in the lower part of the solution.The obliquity of cathode strongly affected the content of diamond grains in the film,and the content reached maximum when the obliquity was kept at 45 degree.The hanging orientation of cathode strongly affected the uniformity of the thickness of the film,and uniform films were deposited when cathode was intermissively circumrotated by 90 degree in the plane itself during deposition.The fluid field in solid-liquid stirred electrolytic solution was analysed by using Computational Fluid Dynamics(CFD).And the influences of agitation velocity, the place of impeller and the obliquity of cathode on the content of diamond grains in the film were explained.With Euler-Lagrange model,the just-suspended speed of impeller in solid-liquid stirred electrolytic tank was predicted by using Zwietering formula,the predicted speed was and it was consistent with experimental result.展开更多
To grow high-quality and large-size monocrystalline silicon at low cost, we proposed a single-seed casting technique. To realize this technique, two challenges—polycrystalline nucleation on the crucible wall and disl...To grow high-quality and large-size monocrystalline silicon at low cost, we proposed a single-seed casting technique. To realize this technique, two challenges—polycrystalline nucleation on the crucible wall and dislocation multiplication inside the crystal—needed to be addressed. Numerical analysis was used to develop solutions for these challenges. Based on an optimized furnace structure and operating conditions from numerical analysis, experiments were performed to grow monocrystalline silicon using the single-seed casting technique. The results revealed that this technique is highly superior to the popular high-performance multicrystalline and multiseed casting mono-like techniques.展开更多
The stir casting technique was used to fabricate aluminum2024matrix hybrid composites reinforced with SiC(5%,mass fraction)and red mud(5%-20%,mass fraction)particles.The developed composites were characterized by usin...The stir casting technique was used to fabricate aluminum2024matrix hybrid composites reinforced with SiC(5%,mass fraction)and red mud(5%-20%,mass fraction)particles.The developed composites were characterized by using scanning electron microscopy(SEM)and electron dispersive spectrum(EDS)techniques.Further,Taguchi’s approach of experimental design was used to examine the tensile strength of the hybrid composites(with minimum number of experiments).It was found that the reinforcing particles were well dispersed and adequately bonded in the hybrid composites.The density and porosity of the hybrid composites were reduced with the increase in reinforcement content.The tensile strength of the composites increased with the increase in the red mud content and the ageing time.The developed model indicated that the red mud content had the highest influence on the tensile strength response followed by the ageing time.Overall,it was found that Al2024/SiC/red mud composites exhibited superior tensile strength(about34%higher)in comparison to the Al2024alloy under optimized conditions.展开更多
文摘In this paper,super-thin free-standing diamond grains-nickel composite film in large area were prepared by using electrotyping method,which were used to make super-thin cutting blades.Scanning electron microscope(SEM) were used to analyse the characteristics of the film.It was found that the agitation velocity and the place of impeller strongly affected the content and uniformity of diamond grains in deposited composite film when the other parameters were the same.The best film was deposited when agitation velocity was 180-220 r/m and the impeller was placed in the lower part of the solution.The obliquity of cathode strongly affected the content of diamond grains in the film,and the content reached maximum when the obliquity was kept at 45 degree.The hanging orientation of cathode strongly affected the uniformity of the thickness of the film,and uniform films were deposited when cathode was intermissively circumrotated by 90 degree in the plane itself during deposition.The fluid field in solid-liquid stirred electrolytic solution was analysed by using Computational Fluid Dynamics(CFD).And the influences of agitation velocity, the place of impeller and the obliquity of cathode on the content of diamond grains in the film were explained.With Euler-Lagrange model,the just-suspended speed of impeller in solid-liquid stirred electrolytic tank was predicted by using Zwietering formula,the predicted speed was and it was consistent with experimental result.
基金partly supported by the New Energy and Industrial Technology Development Organization (NEDO) under the Ministry of Economy,Trade and Industry (METI),Japan
文摘To grow high-quality and large-size monocrystalline silicon at low cost, we proposed a single-seed casting technique. To realize this technique, two challenges—polycrystalline nucleation on the crucible wall and dislocation multiplication inside the crystal—needed to be addressed. Numerical analysis was used to develop solutions for these challenges. Based on an optimized furnace structure and operating conditions from numerical analysis, experiments were performed to grow monocrystalline silicon using the single-seed casting technique. The results revealed that this technique is highly superior to the popular high-performance multicrystalline and multiseed casting mono-like techniques.
文摘The stir casting technique was used to fabricate aluminum2024matrix hybrid composites reinforced with SiC(5%,mass fraction)and red mud(5%-20%,mass fraction)particles.The developed composites were characterized by using scanning electron microscopy(SEM)and electron dispersive spectrum(EDS)techniques.Further,Taguchi’s approach of experimental design was used to examine the tensile strength of the hybrid composites(with minimum number of experiments).It was found that the reinforcing particles were well dispersed and adequately bonded in the hybrid composites.The density and porosity of the hybrid composites were reduced with the increase in reinforcement content.The tensile strength of the composites increased with the increase in the red mud content and the ageing time.The developed model indicated that the red mud content had the highest influence on the tensile strength response followed by the ageing time.Overall,it was found that Al2024/SiC/red mud composites exhibited superior tensile strength(about34%higher)in comparison to the Al2024alloy under optimized conditions.
