冷却间隙对小口径双非球面硫系玻璃镜片模压成型质量的影响

为实现小口径双非球面硫系玻璃镜片的高精度批量制造，通过仿真与实验，对镜片模压成型冷却阶段的冷却间隙进行了研究，揭示了其对镜片成型质量的影响规律。首先，对硫系玻璃模压成型的高温粘弹性力学模型、结构松弛模型以及界面热传递模型进行了分析，并将其应用于仿真研究；其次，对目标镜片进行了模压成型仿真，探讨了冷却间隙条件对镜片内部温度、应力分布以及轮廓偏移量的影响；最后，进行了与仿真研究相对应的模压成型实验，分析了冷却间隙条件对成型镜片表面形状精度PV、表面粗糙度Ra及轮廓偏移量的影响，并将仿真与实验结果进行了对比研究，以验证仿真模型和结果的有效性。仿真分析结果表明:冷却间隙为0.1 mm时，镜片冷却后应力最小，为3.897 MPa；成型镜片非球面ASP1和ASP2的轮廓偏移量最大值分别为1.054 m和0.858 m。实验结果表明:冷却间隙为0.1 mm时，模压得到的成型镜片表面质量最好，ASP1和ASP2的PV值分别为170.8 nm和223.6 nm，Ra值分别为22.7 nm和24.9 nm，轮廓偏移量最大值分别为0.896 m和0.738 m。因此，可确定最小冷却间隙为0.1 mm。仿真与实验结果具有较好的一致性，冷却间隙对小口径双非球面硫系玻璃镜片的成型质量有一定的影响，确定最小冷却间隙可有效提高成型镜片的表面质量。

Effect of cooling gap on molding quality of small diameter dual aspherical chalcogenide glass lenses

In order to realize high-precision mass production of small diameter dual aspherical chalcogenide glass lenses, cooling gap in cooling stage was studied to reveal its influence on lens molding quality through simulation and experiments. Firstly, high temperature viscoelastic mechanical, structural relaxation and interface heat transfer model of the chalcogenide glass molding was analyzed and applied to simulation study. Secondly, molding simulation of target lens was carried out, and influence of cooling gap conditions on internal temperature, stress distribution, and profile deviation of the lenses were discussed. Finally, the molding experiments corresponding to simulation were conducted. The influence of cooling gap conditions on the surface form accuracy PV, surface roughness Ra and profile deviation of the molded lenses were analyzed, and simulation and experimental results were also compared to verify the validity of simulation model and its results. Simulation results show that the stress was the smallest when cooling gap is 0.1 mm, which is 3.897 MPa. The profile deviations of molded lens ASP1 and ASP2 were 1.054 m and 0.858 m, respectively. The experimental results show that surface quality of molded lens with cooling gap of 0.1 mm was the best. The PV values of ASP1 and ASP2 are 170.8 nm and 223.6 nm respectively, Ra values are 22.7 nm and 24.9 nm respectively, and maximum profile deviations are 0.896 m and 0.738 m respectively. Therefore, minimum cooling gap is 0.1 mm. The simulation results showed good agreement with experimental results. The cooling gap has some influence on molding quality of small diameter dual aspherical chalcogenide glass lenses. The determination of minimum cooling gap can effectively improve surface quality of molded lenses.