Nano/microcrystalline composite diamond films were deposited on the holes of WC-6%Co drawing dies by a two-step procedure using alternative carbon sources, i.e., methane for the microcrystalline diamond（MCD） layer a...Nano/microcrystalline composite diamond films were deposited on the holes of WC-6%Co drawing dies by a two-step procedure using alternative carbon sources, i.e., methane for the microcrystalline diamond（MCD） layer and acetone for the nanocrystalline diamond（NCD） layer. Moreover, the monolayer methane-MCD and acetone-NCD coated drawing dies were fabricated as comparisons. The adhesion and wear rates of the diamond coated drawing dies were also tested by an inner hole polishing apparatus. Compared with mono-layer diamond coated drawing die, the composite diamond coated one exhibits better comprehensive performance, including higher adhesive strength and better wear resistance than the NCD one, and smoother surface（Ra=65.3 nm） than the MCD one（Ra=95.6 nm） after polishing at the same time. Compared with the NCD coated drawing die, the working lifetime of the composite diamond coated one is increased by nearly 20 times.展开更多
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
基金supported by Shenzhen Municipality Project (JCYJ20150630114942259)Shenzhen Municipality Science and Technology Planning Project (JSGG20160229202951528, KQJSCX20160301145319, JCYJ20160122143847150)+3 种基金Scientific Equipment Project of Chinese Academy of Sciences (yz201440)Science and Technology Planning Project of Guangdong Province (2014A010105032, 2014A010106016)Natural Science Foundation of Guangdong Province, China (2014A030310482)Guangdong Innovative and Entrepreneurial Research Team Program (2013C090)~~
基金Project(51275302) supported by the National Natural Science Foundation of China
文摘Nano/microcrystalline composite diamond films were deposited on the holes of WC-6%Co drawing dies by a two-step procedure using alternative carbon sources, i.e., methane for the microcrystalline diamond（MCD） layer and acetone for the nanocrystalline diamond（NCD） layer. Moreover, the monolayer methane-MCD and acetone-NCD coated drawing dies were fabricated as comparisons. The adhesion and wear rates of the diamond coated drawing dies were also tested by an inner hole polishing apparatus. Compared with mono-layer diamond coated drawing die, the composite diamond coated one exhibits better comprehensive performance, including higher adhesive strength and better wear resistance than the NCD one, and smoother surface（Ra=65.3 nm） than the MCD one（Ra=95.6 nm） after polishing at the same time. Compared with the NCD coated drawing die, the working lifetime of the composite diamond coated one is increased by nearly 20 times.
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.
