双叶片组合式搅拌器搅拌特性的实验研究

在水和羧甲基纤维素(CMC)水溶液中,对双叶片组合式搅拌器及国内4种搪玻璃搅拌器进行了实验研究,考察了桨形、转速及物料对各种搅拌器搅拌功率和混合时间的影响。实验表明,综合考虑搅拌功率和混合时间,双叶片组合式搅拌器在这两种介质中的混合效率最高。     

玻璃纤维增强尼龙复合材料的力学、耐油脂及耐渗透性能研究

基于尼龙6、尼龙66、透明尼龙61、聚己二酰间苯二甲胺(MXD6)、玻璃纤维和成核剂通过熔融共混法制备了一系列玻璃纤维增强尼龙复合材料,并对常温下复合材料的力学性能进行了对比研究,此外还考察了材料在不同组成时的耐热老化性能、耐油性能及耐渗透性能.结果显示,材料刚性随MXD6加入比例提升而明显增大,而冲击韧性并未出现明显...     

计算机数控技术在砂雕玻璃雕刻机中的应用

在分析砂雕玻璃传统加工工艺技术的基础上,结合计算机图形成像原理,利用计算机数控技术实现了喷砂(sand-b lasting)雕刻玻璃加工的自动化,为砂雕玻璃制品的生产提供了一种新的技术方法。并详细介绍了数控砂雕玻璃加工的技术原理,初步设计了机器的总体结构和数控系统的软硬件结构,举例说明了该技术的实际加工应用效果。     

Mechanical,surface morphological and multi-objective optimization of tribological properties of V2O5 doped lead calcium titanate borosilicate glass ceramics

In the 55[(Pb_xCa_1−x).OTiO₂]-44[2SiO₂.B₂O₃]-1V₂O₅ system, various experimental studies were performed to obtain the mechanical and tribological properties of synthesized glass ceramics (GCs). The surface morphological study and elemental analysis were carried out using scanning electron microscope (SEM) followed by EDAX. The tribological measurements were also performed; based on Taguchi's L₂₅ orthogonal array, considering different GC compositions, sliding speeds and loads. The signal to noise (S/N) ratio was used to identify the influencing parameters on minimizing wear coefficient (k) and coefficient of friction (COF). To improve the tribological properties, the modeling of output responses was performed using response surface methodology (RSM) that was being used for multi-objective optimization using a Pareto optimality approach i.e. Genetic Algorithm (GA). The experimentally achieved k and COF were compared with the earlier work that carried out by the authors for germanium (Ge) doped GC samples. It is observed that the various mechanical properties (Vickers hardness, 29 GPa, Young's modulus, 1808 MPa, and compressive strength, 221 MPa) improved significantly in comparison to the Ge doped GC samples. The improved mechanical and tribological properties of the synthesized GC can be used as a coating material for the structural alloys and machine tool slides in view of its effective wear and corrosion resistance.     

Environmentally friendly CsPbBr3 QDs multicomponent glass with super-stability for optoelectronic devices and up-converted lasing

Ultra-stable CsPbBr₃ perovskite quantum dots (QDs) multicomponent glass with high transmittance was prepared by melt-quenching heat treatment. The average diameter of the CsPbBr₃ QDs was ∼1.96 nm. The resulting glass displayed a high exciton binding energy of 362 ± 18 meV. Notably, these glass-encapsulated materials exhibited excellent resistance to heat, light, and water, superior to that of previously reported perovskite-based materials, and underwent an extremely low rate of Pb leaching during water immersion. Based on the glass, a high-performance white light-emitting diode (WLED) device was fabricated with Commission Internationale de L’Eclairage (CIE) coordinates of (0.3156, 0.3326) and color gamut of ∼113 % National Television Standards Committee (NTSC). The CsPbBr₃ QDs glass without rare earth elements further acted as an optical gain medium, realizing up-conversion lasing with 980-nm laser excitation for the first time. The reversible linear fluorescence response indicates that the glass could be a potential candidate for temperature sensors.     

Erbium doped Bi2O3-B2O3 glass-ceramics containing Bi3B5O12 and CaF2 nanocrystallites for 1.53 μm fiber lasers

Trivalent erbium ions doped Bi₂O₃-B₂O₃ transparent glass ceramics containing CaF₂ were prepared and characterized through X -ray diffraction, scanning electron microscopy, Fourier transform infrared absorption, optical absorption, and near infrared emission for 1.53 μm fiber lasers. The glass ceramics obtained by applying thermal treatment at 575 °C for 5 h and 575 °C for 10 h contain Bi₃B₅O₁₂ and CaF₂ crystallites. The Judd-Ofelt theory was applied to evaluate various spectroscopic and laser characteristic properties. The NIR emission corresponding to the ⁴I_13/2 → ⁴I_15/2 (∼1.53 μm) transition was studied by exciting the samples at 514.5 nm laser radiation. The stimulated emission cross-sections of ∼1.53 μm luminescence were also obtained applying the Mc Cumber theory. The experimental results confirm that the transparent glass ceramic obtained at a thermal treatment of 575 °C for 10 h is more suitable to design fiber lasers for diverse applications in the fields of industry, medicine and scientific research.     

Sinterability,microstructure and compressive strength of porous glass-ceramics from metallurgical silicon slag and waste glass

Porous glass-ceramics have been prepared by the direct sintering of powder mixtures of metallurgical silicon slag and waste glass. The thermal behavior of silicon slag was examined by differential thermal analysis and thermogravimetry to clarify the foaming mechanism of porous glass-ceramics. The mass loss of silicon slag below 700 °C was attributed to the oxidation of amorphous carbon from residual metallurgical coke in the silicon slag, and the mass gain above 800 °C to the passive oxidation of silicon carbide. The porosity of sintered glass-ceramics was characterized in terms of the apparent density and pore size. By simply adjusting the content of waste glass and sintering parameters (i.e. temperature, time and heating rate), the apparent density changed from 0.4 g/cm³ to 0.5 g/cm³, and the pore size from 0.7 mm to 1.4 mm. In addition to the existing crystalline phases in the silicon slag, the gehlenite phase appeared in the sintered glass-ceramics. The compressive strength of porous glass-ceramics firstly increased and then decreased with the sintering temperature, reaching a maximal value of 1.8 MPa at 750 °C. The mechanical strength was primarily influenced by the crystallinity of glass-ceramics and the interfaces between the crystalline phases and the glassy matrix. These sintered porous glass-ceramics exhibit superior properties such as light-weight, heat-insulation and sound-absorption, and could found their potential applications in the construction decoration.     

碲卤系红外玻璃光纤的制备及性质

研究了碲卤系中远红外玻璃光纤的制备及性质,提出了制备碲卤系玻璃预制棒的一个改进的方法,用该方法制备出了高透光率的中远红外玻璃,拉制出了在１０．６μｍ附近光损耗约为１０ｄＢ／ｍｒ Ｔｅ３Ｓｅ４Ｉ３玻璃光纤,并测试了这种玻璃纤维的最小抗弯曲率半径。     

Redox State of Iron and Its Related Effects in the CaO–P2O5–Fe2O3 Glasses

Iron exists in Fe²⁺ and Fe³⁺ states in CaO–P₂O₅–Fe₂O₃ glasses and they impart characteristic optical absorption bands that allow analysis of relative proportion of the two species. This communication reports the redox states of glasses melted under air, argon, and oxygen atmospheres and relates them to the dissolution rates. The dissolution rate was found to be related to the redox state and it is lowered if the glass is melted under oxidizing atmospheres.     

数字光盘玻璃基片的三步抛光技术

为得到超光滑的数字光盘母盘玻璃基片表面,研究玻璃基片的亚纳米级抛光技术。分别采用2 m、0.3 m超细氧化铈抛光液以及纳米氧化硅抛光液进行三步化学机械抛光(Chemical mechanical polishing, CMP),抛光后最终表面粗糙度Ra达到0.44 nm,为目前报道的数字光盘母盘玻璃基片抛光的最低值。原子力显微镜分析表明,抛光后的表面超光滑且无微观缺陷。通过对玻璃基片CMP中机械作用及化学作用进行分析,对抛光机理进行了探讨。