For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest o...For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest on wear phenomenon describing simply without analyzing the genesis of wear phenomenon and interpreting the formation process of tool wear in mechanics. For in depth understanding of the tool wear and its effect on surface roughness in diamond cutting of glass, experiments of diamond turning with cutting distance increasing gradually are carried out on soda-lime glass. The wear morphology of rake face and flank face, the corresponding surface features of workpiece and the surface roughness, and the material compositions of flank wear area are detected. Experimental results indicate that the flank wear is predominant in diamond cutting glass and the flank wear land is characterized by micro-grooves, some smooth crater on the rake face is also seen. The surface roughness begins to increase rapidly, when the cutting mode changes from ductile to brittle for the aggravation of tool wear with the cutting distance over 150 m. The main mechanisms of inducing tool wear in diamond cutting of glass are diffusion, mechanical friction, thermo-chemical action and abrasive wear. The proposed research makes analysis and research from wear mechanism on the tool wear and its effect on surface roughness in diamond cutting of glass, and provides theoretical basis for minimizing the tool wear in diamond cutting brittle materials, such as optical glass.展开更多
The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality proce...The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 ~tm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5x 107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.展开更多
The diffusion property of sulfur on the soda-lime-silicate float glass surface was studied by using secondary ion mass spectroscopy（SIMS）.According to the Fick＇s Second Law,two models of diffusion of sulfur on the ...The diffusion property of sulfur on the soda-lime-silicate float glass surface was studied by using secondary ion mass spectroscopy（SIMS）.According to the Fick＇s Second Law,two models of diffusion of sulfur on the glass surface were built.When the diffusion of sulfate（S^6＋） is considered uniquely,the concentration-depth profile of sulfur can not be fitted very well,especially on the top surfaces of the air side and tin side of float glass.So the diffusion of sulfide（S^2-） on the profile of sulfur can not be ignored.The concentration-depth profile of sulfur on both sides of glass can be fitted more exactly when both S^6＋ and S^2- are considerd.Based on the above-mentioned fitting results,it is concluded that the diffusion coefficents of S^6＋ and S^2- of tin side are larger than those of the air side.Moreover,the diffusion coefficents are related to the contacted medium.展开更多
To produce high-purity silica sand usable for glass making, the present study was carried out. The objective of this work was to increase the silicon dioxide (SiO<sub>2</sub>) content to at least 99% using...To produce high-purity silica sand usable for glass making, the present study was carried out. The objective of this work was to increase the silicon dioxide (SiO<sub>2</sub>) content to at least 99% using a simple process without chemical input. The raw sand samples were taken from the Ivorian sedimentary basin, from Maféré and Assinie areas, C<span style="white-space:nowrap;">ô</span>te d’Ivoire. Wet sieving and attrition technique were used for the purification process. The results from the energy dispersive spectrometer (EDS) analyses of the raw and treated samples show a significant increase of silica content and a significant reduction of impurities. The silica content (SiO<sub>2</sub>) of the sand of Maféré increases from 98.73% ± 0.15% to 99.92% ± 0.05%. And the sand of Assinie increased from 98.82% ± 0.67% in the raw samples to 99.44% ± 0.27% after treatment. The rate of iron oxide and alumina is reduced in these sands. Moreover, the sand of Maféré contains 53.2% of grains of size lower than 500 microns and that of Assinie contains 29.30%. Regarding the chemical composition of these purified sands, they meet the standard BS2975s, the American Ceramic Society and the National Bureau of Standards for window glass making.展开更多
We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various tem...We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various temperatures. Structural change of the grating is observed by an optical microscope. Absorption spectra indicate that colour centres are induced after the laser irradiation, and they decrease with increasing annealing temperature. Au nanoparticles are precipitated at high temperatures （≥ 600℃）. The mechanisms of the phenomena are discussed.展开更多
Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical...Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical strength.Sandblasting by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of inclination.To characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a profilometer.To determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular supports.The effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.展开更多
Vertically-oriented graphene （VG） has many advantages over flat lying graphene, including a large surface area, exposed sharp edges, and non-stacking three-dimensional geometry. Recently, VG nanosheets assembled on ...Vertically-oriented graphene （VG） has many advantages over flat lying graphene, including a large surface area, exposed sharp edges, and non-stacking three-dimensional geometry. Recently, VG nanosheets assembled on specific substrates have been used for applications in supersensitive gas sensors and high-performance energy storage devices. However, to realize these intriguing applications, the direct growth of high-quality VG on a functional substrate is highly desired. Herein, we report the direct synthesis of VG nanosheets on traditional soda-lime glass due to its low-cost, good transparency, and compatibility with many applications encountered in daily life. This synthesis was achieved by a direct-current plasma enhanced chemical vapor deposition （dc-PECVD） route at 580℃, which is right below the softening point of the glass, and featured a scale-up size - 6 inches. Particularly, the fabricated VG nanosheets/glass hybrid materials at a transmittance range of 97%-34% exhibited excellent solarthermal performances, reflected by a 70%-130% increase in the surface temperature under simulated sunlight irradiation. We believe that this graphene glass hybrid material has great potential for use in future transparent ＂green-warmth＂ construction materials.展开更多
This paper was to investigate the optical and luminescence properties of Sm^(3+) doped SLB glasses by a melt quenching technique. The optical and luminescence properties of the prepared glass samples were investigated...This paper was to investigate the optical and luminescence properties of Sm^(3+) doped SLB glasses by a melt quenching technique. The optical and luminescence properties of the prepared glass samples were investigated via absorption and photoluminescence spectra, respectively. The related physical and optical parameters were also calculated. From optical absorption measurements, the transition ~6H_(5/2) → ~6P_(3/2) at 403 nm has a higher spectral intensity and is a hypersensitive transition. From photoluminescence spectra, four prominent emission spectra appear. The most intense band is located at ~4G_(5/2) →~6H_(9/2)(599 nm), which is the characteristic emission range of Sm^(3+) ions with the reddish orange color. The experimental decay time of the ~4G_(5/2) level of Sm^(3+) SLB glasses was determined. The decay time decreases from 1.367 to 0.333 ms with increasing the content of Sm^(3+). The color coordinates(x, y) of the prepared glasses passes through the reddish-orange region in the CIE 1931 diagram and are suitable for orange LEDs, optoelectronics, and solidstate lighting. The further investigation on the optimization of the dopant content in the SLB glasses was suggested.展开更多
基金supported by National Natural Science Foundation of China(Grant No. 50775057)
文摘For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest on wear phenomenon describing simply without analyzing the genesis of wear phenomenon and interpreting the formation process of tool wear in mechanics. For in depth understanding of the tool wear and its effect on surface roughness in diamond cutting of glass, experiments of diamond turning with cutting distance increasing gradually are carried out on soda-lime glass. The wear morphology of rake face and flank face, the corresponding surface features of workpiece and the surface roughness, and the material compositions of flank wear area are detected. Experimental results indicate that the flank wear is predominant in diamond cutting glass and the flank wear land is characterized by micro-grooves, some smooth crater on the rake face is also seen. The surface roughness begins to increase rapidly, when the cutting mode changes from ductile to brittle for the aggravation of tool wear with the cutting distance over 150 m. The main mechanisms of inducing tool wear in diamond cutting of glass are diffusion, mechanical friction, thermo-chemical action and abrasive wear. The proposed research makes analysis and research from wear mechanism on the tool wear and its effect on surface roughness in diamond cutting of glass, and provides theoretical basis for minimizing the tool wear in diamond cutting brittle materials, such as optical glass.
基金supported by National Natural Science Foundation for Young Scholars of China(Grant No.51205053)National Natural Science Foundation of China(Grant No.51075064)
文摘The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 ~tm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5x 107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.
基金Funded by National Natural Science Foundation of China(NSFC)(No.50972136)National Science and Technology S upporting P rogram(No.2015BAA02B00)+1 种基金National Key Technologies R&D Program(No.2016YFB0303900)the Fundamental Research Funds of State Key Laboratory for Advanced Technology of Float Glass
文摘The diffusion property of sulfur on the soda-lime-silicate float glass surface was studied by using secondary ion mass spectroscopy（SIMS）.According to the Fick＇s Second Law,two models of diffusion of sulfur on the glass surface were built.When the diffusion of sulfate（S^6＋） is considered uniquely,the concentration-depth profile of sulfur can not be fitted very well,especially on the top surfaces of the air side and tin side of float glass.So the diffusion of sulfide（S^2-） on the profile of sulfur can not be ignored.The concentration-depth profile of sulfur on both sides of glass can be fitted more exactly when both S^6＋ and S^2- are considerd.Based on the above-mentioned fitting results,it is concluded that the diffusion coefficents of S^6＋ and S^2- of tin side are larger than those of the air side.Moreover,the diffusion coefficents are related to the contacted medium.
文摘To produce high-purity silica sand usable for glass making, the present study was carried out. The objective of this work was to increase the silicon dioxide (SiO<sub>2</sub>) content to at least 99% using a simple process without chemical input. The raw sand samples were taken from the Ivorian sedimentary basin, from Maféré and Assinie areas, C<span style="white-space:nowrap;">ô</span>te d’Ivoire. Wet sieving and attrition technique were used for the purification process. The results from the energy dispersive spectrometer (EDS) analyses of the raw and treated samples show a significant increase of silica content and a significant reduction of impurities. The silica content (SiO<sub>2</sub>) of the sand of Maféré increases from 98.73% ± 0.15% to 99.92% ± 0.05%. And the sand of Assinie increased from 98.82% ± 0.67% in the raw samples to 99.44% ± 0.27% after treatment. The rate of iron oxide and alumina is reduced in these sands. Moreover, the sand of Maféré contains 53.2% of grains of size lower than 500 microns and that of Assinie contains 29.30%. Regarding the chemical composition of these purified sands, they meet the standard BS2975s, the American Ceramic Society and the National Bureau of Standards for window glass making.
基金Supported by the National Natural Science Foundation of China under Grant No 50672087, and the National Basic Research Programme of China under Grant No 2006CB806000b.
文摘We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various temperatures. Structural change of the grating is observed by an optical microscope. Absorption spectra indicate that colour centres are induced after the laser irradiation, and they decrease with increasing annealing temperature. Au nanoparticles are precipitated at high temperatures （≥ 600℃）. The mechanisms of the phenomena are discussed.
文摘Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical strength.Sandblasting by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of inclination.To characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a profilometer.To determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular supports.The effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.
文摘Vertically-oriented graphene （VG） has many advantages over flat lying graphene, including a large surface area, exposed sharp edges, and non-stacking three-dimensional geometry. Recently, VG nanosheets assembled on specific substrates have been used for applications in supersensitive gas sensors and high-performance energy storage devices. However, to realize these intriguing applications, the direct growth of high-quality VG on a functional substrate is highly desired. Herein, we report the direct synthesis of VG nanosheets on traditional soda-lime glass due to its low-cost, good transparency, and compatibility with many applications encountered in daily life. This synthesis was achieved by a direct-current plasma enhanced chemical vapor deposition （dc-PECVD） route at 580℃, which is right below the softening point of the glass, and featured a scale-up size - 6 inches. Particularly, the fabricated VG nanosheets/glass hybrid materials at a transmittance range of 97%-34% exhibited excellent solarthermal performances, reflected by a 70%-130% increase in the surface temperature under simulated sunlight irradiation. We believe that this graphene glass hybrid material has great potential for use in future transparent ＂green-warmth＂ construction materials.
文摘This paper was to investigate the optical and luminescence properties of Sm^(3+) doped SLB glasses by a melt quenching technique. The optical and luminescence properties of the prepared glass samples were investigated via absorption and photoluminescence spectra, respectively. The related physical and optical parameters were also calculated. From optical absorption measurements, the transition ~6H_(5/2) → ~6P_(3/2) at 403 nm has a higher spectral intensity and is a hypersensitive transition. From photoluminescence spectra, four prominent emission spectra appear. The most intense band is located at ~4G_(5/2) →~6H_(9/2)(599 nm), which is the characteristic emission range of Sm^(3+) ions with the reddish orange color. The experimental decay time of the ~4G_(5/2) level of Sm^(3+) SLB glasses was determined. The decay time decreases from 1.367 to 0.333 ms with increasing the content of Sm^(3+). The color coordinates(x, y) of the prepared glasses passes through the reddish-orange region in the CIE 1931 diagram and are suitable for orange LEDs, optoelectronics, and solidstate lighting. The further investigation on the optimization of the dopant content in the SLB glasses was suggested.
