There are mainly two kinds of equipment to produce synthetic diamond,namely belt press & cubic press.It has been customary in the industry to regard synthetic diamond produced by cubic press is inferior to that ma...There are mainly two kinds of equipment to produce synthetic diamond,namely belt press & cubic press.It has been customary in the industry to regard synthetic diamond produced by cubic press is inferior to that made by belt press.With the on-going improvement in technology,know-how & accumulated experiences, perhaps it’ s time for us to review the qualities & performances of synthetic diamond made by the cubic press more objectively.Studies were carried out on the performances of the two kinds of diamond by choosing from top brands & top qualities,with coarser mesh sizes 20/30 & 30/40.Comparisons were made on parameters, such as TI,TTI,PPC,bulk density,compact,roughness and arealight.And the diamonds chosen were used to produce the relevant diamond core drill bits and saw blades,their respective cutting performances such as cutting efficiency,segments consumption were measured and reported in this paper.The report demonstrates that producing the high quality diamond does not depend on the type of presses(Belt or Cubic) but rather on the know-how,technology and what it is made.展开更多
The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site...The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site core electron as a reference energy level. For the strained diamond/c-BN superlattice, the valence band offset of around 1.50 eV is in good agreement with those using all the electrons methods. As for the longitudinally relaxed superlattice, the valence band offset of around 1.28 eV is smaller than that of the strained superlattice. The reason for this is mainly due to the split of the valence band maximum caused by the anisotropic strain.展开更多
The development of China as the world’s manufacturing house is best exemplified in the industry of diamond superabrasives.Diamond is indispensable in the creation of industrial infrastructure,including the constructi...The development of China as the world’s manufacturing house is best exemplified in the industry of diamond superabrasives.Diamond is indispensable in the creation of industrial infrastructure,including the construction of roads and building of houses.The world’s diamond was provided mainly by countries outside China in last century.However,a"great leap forward"has taken shape with rapid expansion in Chinese diamond-making capabilities from the enlargement of the equipment(cubic presses) and improvements in diamond yield and product quality in the end of last century.At the turn of this century,China outpaced the rest world combined in the total diamond output,became the largest producer in the world indubitably.In 2007,China produced nearly 4.4 billion carats,80%of the world’s diamond total output.The Chinese diamond well accepted in the world can be seen in the export statistics of China & import statistics of developed countries in this paper.For example,59%of USA imported diamonds were from China in 2007;in Japan, 40%. This report contains a survey of some main industrial sectors that use diamond superabrasives.Overall,22 tables and figures are used to portray the many facets of superabrasives,including cubic boron nitride.The report also discusses several challenges facing Chinese diamonds,such as the vast price difference between imported diamond grit produced outside China and domestic supply.This paper also presents an outlook of the future development of the Chinese superabrasives industry basing on the Chinese macroeconomics and the recent data of the end-users as well as their future development trend.The paper concludes by proposing that although remarkable achievements have been made in the past 45 years,given the fact that Chinese superabrasives industry still lags behind that from the advanced countries on a multitude of variables,further endeavor should be made to make China a super country in the superabrasives industry in the world.展开更多
More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> techno...More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> technology with patterned diamond seeding can boost the production yield of coarse mesh diamonds（e.g. 30/40）.Moreover,the DiaMind crystals formed contain a visible core.This diamond-in-diamond architecture allows self-sharpening during sawing application.Furthermore,a revolutionary polycrystalline diamond superabrasive with cubical shape was fabricated to further increase the sawing efficiency and tool longevity.Such DiaCube<sup>TM</sup> polygrits were made tools by brazing them on pearls of wire saws and on the surface of turbo grinders. The pros and cons of major designs of high-pressure equipment for diamond synthesis were discussed with the recommendation to combine the merits of belt apparatus and cubic press.This tooling synergism may increase diamond yield at reduced cost for massive production of saw grits. In 1997 Sung Chien-Min filed a series US patents that described the art of making patterned diamond tools with diamond grits forming an array in three dimensions.He also made the debut of the world’ s first brazing tools with patterned diamond distribution at the stone exhibition in Verona in 1998（also in Nuremberg in 1999）.The patterned diamond saws were introduced by Korean companies in 2005 with the demonstration of increased cutting speeds and prolonged tool lives.展开更多
文摘There are mainly two kinds of equipment to produce synthetic diamond,namely belt press & cubic press.It has been customary in the industry to regard synthetic diamond produced by cubic press is inferior to that made by belt press.With the on-going improvement in technology,know-how & accumulated experiences, perhaps it’ s time for us to review the qualities & performances of synthetic diamond made by the cubic press more objectively.Studies were carried out on the performances of the two kinds of diamond by choosing from top brands & top qualities,with coarser mesh sizes 20/30 & 30/40.Comparisons were made on parameters, such as TI,TTI,PPC,bulk density,compact,roughness and arealight.And the diamonds chosen were used to produce the relevant diamond core drill bits and saw blades,their respective cutting performances such as cutting efficiency,segments consumption were measured and reported in this paper.The report demonstrates that producing the high quality diamond does not depend on the type of presses(Belt or Cubic) but rather on the know-how,technology and what it is made.
基金supported by the National Natural Science Foundation of China (Grant No.60877017)the Innovation Program of Shanghai Municipal Education Commission (Grant No.08YZ04)the Shanghai Leading Academic Discipline Project (Grant No.S30107)
文摘The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride （c-BN） （110） superlattice are investigated by the plane wave density functional theory approach and using the on-site core electron as a reference energy level. For the strained diamond/c-BN superlattice, the valence band offset of around 1.50 eV is in good agreement with those using all the electrons methods. As for the longitudinally relaxed superlattice, the valence band offset of around 1.28 eV is smaller than that of the strained superlattice. The reason for this is mainly due to the split of the valence band maximum caused by the anisotropic strain.
文摘The development of China as the world’s manufacturing house is best exemplified in the industry of diamond superabrasives.Diamond is indispensable in the creation of industrial infrastructure,including the construction of roads and building of houses.The world’s diamond was provided mainly by countries outside China in last century.However,a"great leap forward"has taken shape with rapid expansion in Chinese diamond-making capabilities from the enlargement of the equipment(cubic presses) and improvements in diamond yield and product quality in the end of last century.At the turn of this century,China outpaced the rest world combined in the total diamond output,became the largest producer in the world indubitably.In 2007,China produced nearly 4.4 billion carats,80%of the world’s diamond total output.The Chinese diamond well accepted in the world can be seen in the export statistics of China & import statistics of developed countries in this paper.For example,59%of USA imported diamonds were from China in 2007;in Japan, 40%. This report contains a survey of some main industrial sectors that use diamond superabrasives.Overall,22 tables and figures are used to portray the many facets of superabrasives,including cubic boron nitride.The report also discusses several challenges facing Chinese diamonds,such as the vast price difference between imported diamond grit produced outside China and domestic supply.This paper also presents an outlook of the future development of the Chinese superabrasives industry basing on the Chinese macroeconomics and the recent data of the end-users as well as their future development trend.The paper concludes by proposing that although remarkable achievements have been made in the past 45 years,given the fact that Chinese superabrasives industry still lags behind that from the advanced countries on a multitude of variables,further endeavor should be made to make China a super country in the superabrasives industry in the world.
文摘More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCan<sup>TM</sup> technology with patterned diamond seeding can boost the production yield of coarse mesh diamonds（e.g. 30/40）.Moreover,the DiaMind crystals formed contain a visible core.This diamond-in-diamond architecture allows self-sharpening during sawing application.Furthermore,a revolutionary polycrystalline diamond superabrasive with cubical shape was fabricated to further increase the sawing efficiency and tool longevity.Such DiaCube<sup>TM</sup> polygrits were made tools by brazing them on pearls of wire saws and on the surface of turbo grinders. The pros and cons of major designs of high-pressure equipment for diamond synthesis were discussed with the recommendation to combine the merits of belt apparatus and cubic press.This tooling synergism may increase diamond yield at reduced cost for massive production of saw grits. In 1997 Sung Chien-Min filed a series US patents that described the art of making patterned diamond tools with diamond grits forming an array in three dimensions.He also made the debut of the world’ s first brazing tools with patterned diamond distribution at the stone exhibition in Verona in 1998（also in Nuremberg in 1999）.The patterned diamond saws were introduced by Korean companies in 2005 with the demonstration of increased cutting speeds and prolonged tool lives.
