Micro/nanostructured components play an important role in micro-optics and optical engineering,tribology and surface engineering,and biological and biomedical engineering,among other fields.Precision glass molding tec...Micro/nanostructured components play an important role in micro-optics and optical engineering,tribology and surface engineering,and biological and biomedical engineering,among other fields.Precision glass molding technology is the most efficient method of manufacturing micro/nanostructured glass components,the premise of which is meld manufacturing with complementary micro/nanostructures.Numerous mold manufacturing methods have been developed to fabricate extremely small and high-quality micro/nanostructures to satisfy the demands of functional micro/nanostructured glass components for various applications.Moreover,the service performance of the mold should also be carefully considered.This paper reviews a variety of technologies for manufacturing micro/nanostructured molds.The authors begin with an introduction of the extreme requirements of mold materials.The following section provides a detailed survey of the existing micro/nanostructured mold manufacturing techniques and their corresponding mold materials,including nonmechanical and mechanical methods.This paper concludes with a detailed discussion of the authors recent research on nickel-phosphorus(Ni-P)mold manufacturing and its service performance.展开更多
Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper ...Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper presents an overview of optical microstructure fabrication through glass molding and highlights the applications of optical microstructures in mold fabrication and glass molding. The glass-mold interface friction and adhesion are also discussed. Moreover, the latest advance- ments in glass molding technologies are detailed, including new mold materials and their fabrication methods, viscoelastic constitutive modeling of glass, and micro- structure molding process, as well as ultrasonic vibration- assisted molding technology.展开更多
It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding （PGM） has thus been developed to re...It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding （PGM） has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carded out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable tempera- ture variation, the glass viscosity can change from 10s to 10t2 Pa-s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxa- tion in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.展开更多
In the glass molding process,the sticking reaction and fatigue wear between the glass and mold hinder the service life and functional application of the mold at the elevated temperature.To improve the chemical inertne...In the glass molding process,the sticking reaction and fatigue wear between the glass and mold hinder the service life and functional application of the mold at the elevated temperature.To improve the chemical inertness and anti-friction properties of the mold,an amorphous carbon coating was synthesized on the tungsten carbide-cobalt(WC–8Co)substrate by magnetron sputtering.The friction behavior between the glass and carbon coating has a significant influence on the functional protection and service life of the mold.Therefore,the glass ring compression tests were conducted to measure the friction coefficient and friction force of the contact interface between the glass and amorphous carbon coating at the high temperature.Meanwhile,the detailed characterization of the amorphous carbon coating was performed to study the microstructure evolution and surface topography of the amorphous carbon coating during glass molding process by scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Ramon spectroscopy,and atomic force microscope(AFM).The results showed that the amorphous carbon coating exhibited excellent thermal stability,but weak shear friction strength.The friction coefficient between the glass and coating depended on the temperature.Besides,the service life of the coating was governed by the friction force of the contact interface,processing conditions,and composition diffusion.This work provides a better understanding of the application of carbon coatings in the glass molding.展开更多
Acrylonitrile-butadiene-Styrene (ABS), with and without calcium carbonate (calcite) particles,was used as the matrix for reinforcement with as-received short-glass fibres (were originallytreated by the manufacturer) a...Acrylonitrile-butadiene-Styrene (ABS), with and without calcium carbonate (calcite) particles,was used as the matrix for reinforcement with as-received short-glass fibres (were originallytreated by the manufacturer) and sized short-glass fibres with two amino-silane coupling agents.The calcite particle content is 0, 11.7 and 23.5 vol. pct for the matrices. The glass fiber contentis 0, 10 and 15 vol. pct. The matrix materials and corresponding composites were compoundedusing a twin screw extruder and dumbbell-shaped tensile bars were prepared with an injectionmolding process. The tensile and flexural properties as well as the unnotched and notchedCharpy impact energies of short glass fibre/calcite/ABS composites were studied in this paper.The effects of fibres, fibre surface treatments and particles on these mechanical properties ofthe composites were discussed in detail. An importarit information was obtained, which is thatthe tensile and flexural strengths of hybrid SGF/calcite/ABS composites are the same as thoseof corresponding fibre composites when the ratio of the interfacial adhesion strength betweenparticles and matrix to that between fibres and matrix is higher than certain value. otherwise theformer are lower than the latter.展开更多
Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold g...Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold glass tightly,thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem,a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly,a pair of permanent magnets is introduced as energy source,followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold,which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding,the magnetic energy product and the magnetized filed distributions,and the re-checking method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force,which not only protects glass but self-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface,with no scratches and cracks on the glass and no slight glass movements in the mold cavity.展开更多
基金This work was financially supported by National Natural Science Foundation of China(Nos.51775046&51875043&52005040)the China Postdoctoral Science Foundation(No.2019M660480)+1 种基金the Beijing Municipal Natural Sci-ence Foundation(JQ20014)The authors would also like to acknowledge support from the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Insti-tutions of China(No.151052).
文摘Micro/nanostructured components play an important role in micro-optics and optical engineering,tribology and surface engineering,and biological and biomedical engineering,among other fields.Precision glass molding technology is the most efficient method of manufacturing micro/nanostructured glass components,the premise of which is meld manufacturing with complementary micro/nanostructures.Numerous mold manufacturing methods have been developed to fabricate extremely small and high-quality micro/nanostructures to satisfy the demands of functional micro/nanostructured glass components for various applications.Moreover,the service performance of the mold should also be carefully considered.This paper reviews a variety of technologies for manufacturing micro/nanostructured molds.The authors begin with an introduction of the extreme requirements of mold materials.The following section provides a detailed survey of the existing micro/nanostructured mold manufacturing techniques and their corresponding mold materials,including nonmechanical and mechanical methods.This paper concludes with a detailed discussion of the authors recent research on nickel-phosphorus(Ni-P)mold manufacturing and its service performance.
基金Acknowledgements This work was supported by the National Basic Research Program of China （Grant No. 2015CB059900） and the National Natural Science Foundation of China （Grant No. 51375050）.
文摘Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper presents an overview of optical microstructure fabrication through glass molding and highlights the applications of optical microstructures in mold fabrication and glass molding. The glass-mold interface friction and adhesion are also discussed. Moreover, the latest advance- ments in glass molding technologies are detailed, including new mold materials and their fabrication methods, viscoelastic constitutive modeling of glass, and micro- structure molding process, as well as ultrasonic vibration- assisted molding technology.
文摘It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding （PGM） has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carded out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable tempera- ture variation, the glass viscosity can change from 10s to 10t2 Pa-s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxa- tion in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of Guangdong Province(2018A030313466)the assistance on the observation received from the Electron Microscope Center of the Shenzhen University.
文摘In the glass molding process,the sticking reaction and fatigue wear between the glass and mold hinder the service life and functional application of the mold at the elevated temperature.To improve the chemical inertness and anti-friction properties of the mold,an amorphous carbon coating was synthesized on the tungsten carbide-cobalt(WC–8Co)substrate by magnetron sputtering.The friction behavior between the glass and carbon coating has a significant influence on the functional protection and service life of the mold.Therefore,the glass ring compression tests were conducted to measure the friction coefficient and friction force of the contact interface between the glass and amorphous carbon coating at the high temperature.Meanwhile,the detailed characterization of the amorphous carbon coating was performed to study the microstructure evolution and surface topography of the amorphous carbon coating during glass molding process by scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Ramon spectroscopy,and atomic force microscope(AFM).The results showed that the amorphous carbon coating exhibited excellent thermal stability,but weak shear friction strength.The friction coefficient between the glass and coating depended on the temperature.Besides,the service life of the coating was governed by the friction force of the contact interface,processing conditions,and composition diffusion.This work provides a better understanding of the application of carbon coatings in the glass molding.
文摘Acrylonitrile-butadiene-Styrene (ABS), with and without calcium carbonate (calcite) particles,was used as the matrix for reinforcement with as-received short-glass fibres (were originallytreated by the manufacturer) and sized short-glass fibres with two amino-silane coupling agents.The calcite particle content is 0, 11.7 and 23.5 vol. pct for the matrices. The glass fiber contentis 0, 10 and 15 vol. pct. The matrix materials and corresponding composites were compoundedusing a twin screw extruder and dumbbell-shaped tensile bars were prepared with an injectionmolding process. The tensile and flexural properties as well as the unnotched and notchedCharpy impact energies of short glass fibre/calcite/ABS composites were studied in this paper.The effects of fibres, fibre surface treatments and particles on these mechanical properties ofthe composites were discussed in detail. An importarit information was obtained, which is thatthe tensile and flexural strengths of hybrid SGF/calcite/ABS composites are the same as thoseof corresponding fibre composites when the ratio of the interfacial adhesion strength betweenparticles and matrix to that between fibres and matrix is higher than certain value. otherwise theformer are lower than the latter.
基金National Natural Science Foundation of China(No.51303027)Program for New Century Excellent Talents in Fujian Province University,China(No.NCETFJ-2010)+1 种基金Research Fund for Fujian Provincial University,China(No.JK2010038)Research Fund of Fujian Education Department,China(No.JA11189)
文摘Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold glass tightly,thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem,a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly,a pair of permanent magnets is introduced as energy source,followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold,which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding,the magnetic energy product and the magnetized filed distributions,and the re-checking method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force,which not only protects glass but self-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface,with no scratches and cracks on the glass and no slight glass movements in the mold cavity.
