Papers by Author: Ke Jun Zhu

Abstract: Optical glass is widely used as the most important material in optical field in recent years. Glass molding press (GMP) has been employed as a promising technique to manufacture optical components in mass production. Heating time and annealing time are the key factors which influence the production cycle. In this paper, an effective method of improving the heating or the annealing effectiveness is to increase the area exposed to the cooling or hot nitrogen by means of adding slots. In the same condition, four models with different slots were built. Based on the theoretical analysis of glass heating and annealing property in the molding process, finite element simulation was carried out. The results showed that the model with slots may decrease the heating and annealing time.

Abstract: Glass forming process is a high-volume fabrication method for producing glass containers. In this paper, the mechanisms of glass forming process were analyzed. Combined the coupled thermo-mechanical analysis with the finite element method (FEM) simulation, it was carried out to analyze the key process factors such as forming temperature, forming pressure, friction coefficient. The results show that forming pressure has the greatest influence on the stress.

Abstract: Glass lens molding is a high-volume fabrication method for producing optical components. In this paper, combined with the orthogonal test method and finite element method (FEM) simulation, the coupled thermo-mechanical analysis was carried out to analyze the key process factors. In order to reduce the testing time, an orthogonal test with three sets of level factors and three parameters is conducted to obtain the optimal molding process parameters. The result shows that the most significant parameter is molding velocity, the other effect parameters are molding temperature and friction coefficient. According to the previous analysis of orthogonal experiment, it is shown that the best optimal finishing process parameters were A2B1C1.

Abstract: Glass molding is a high-volume fabrication method for producing optical components. Non-isothermal glass molding press (NGM) was proposed to fabricate optical glass, and its characteristics were studied by finite element method (FEM) simulation. The coupled thermo-mechanical analysis was carried out to analyze the key factors such as temperature distribution, stress distribution and strain distribution. The non-isothermal and isothermal glass molding (IGM) was studied, and optimal temperature match between glass and mold was obtained.

Abstract: With the rapid development of opto-electronics communications, optics, aerospace and other industries, ultra-precision aspheric glass lenses are widely used in middle/high-grade optical opponent because of its high resolution and imaging quality. To achieve ultra-precision molding pressing of micro-lens, ultra-precision mold must be fabricated firstly. In this paper, some key new technologies were proposed for fabricating ultra-precision mold of small-size aspheric optical lens. A method of finite element simulation was employed to predict mould pressing process of the glass lens for correcting molds and improving the formation efficiency. An ultra-precision inclined-axis grinding and error compensation technology was also used to improve form accuracy of micro lens mold.

Abstract: Glass lens molding is an effective approach to produce precision micro aspheric glass lens at high efficiency. In this paper, a new two-step isothermal glass molding process was proposed. The mechanisms of new molding process were analyzed. Finite element simulation was conducted to analyze the key factors such as the pressing load, die damage, molding time and residual stress of lens during the traditional molding and the two-step isothermal molding. The results showed that the two-step isothermal glass lens molding process may decrease residual stress and improve stress and strain distribution. Furthermore, prolong the service life of die.

Abstract: Optical glass is widely used as the most important basic material in optical field. In this paper, four different shape finishing tools are designed for polishing flat K9 glass by using magneto-rheological finishing process. Influences of the finishing tool’s shape on surface roughness are investigated and analyzed under different related parameters such as finishing time, rotational speed of tool and finishing gap. The result shows that the slotted tool could obtain better surface roughness than the non-slotted tool under the same conditions. Through changing the magnetic field intensity, finishing gap, rotational speed of tool and finishing time, an orthogonal experiment is conducted to obtain the optimal finishing process parameters.