Key Engineering Materials Vol. 837

Abstract: Viscosity-temperature characteristics of high borosilicate glass were investigated in detail by means of rotor viscometer and dilatometer. The neck-down deformation process of glass tube was simulated by Polyflow software, and the simulation was verified by the secondary drawing of glass perform. The results showed that the high temperature viscosity of borosilicate glass is higher compared to that of ordinary optical glass. In the high temperature stage, the fitting curves of VFT, AV, AG and MYEGA models are all in good agreement with the tested curve. However, in the low temperature stage, only viscosity fitted by VFT model is close to the tested value. Based on Navier-Stokes equation, a mathematical model of neck-down deformation of glass tube during secondary drawing is established. It is found that viscosity is the key material intrinsic factor affecting neck-down process of glass tube. The distribution of inner and outer diameters of glass tube along the drawing direction is simulated and analyzed under different feeding and drawing rates. The deviation between the steady-state dimension simulated and that actually drawn is only ±0.06 mm.

Abstract: Preparation, microstructure and mechanical performance of novel supplementary cementing materials prepared with electroplating sludge and steel slag as raw materials were studied. It was found that the electroplating sludge could be mixed with steel slag at appropriate ratios to make SCMs that posse certain compressive strength. The results shows that the supplementary cementing materials prepared in this article can increase the compressive strengths of cement when it substitutes for cement in appropriate proportion. The microstructure and hydration products of cement with SCMs were examined by XRD and SEM. The results indicated that the content of calcium hydroxide formed in paste significantly reduced and Aft increased, as the content of the supplementary cementing materials increased. In addition, the heavy metals elements in the electroplating sludge could be effective cured in cement pastes and reduced the pollution to the environment.

Abstract: Effect of Ti (C,N) based cermets granule on the microstructure, mechanical properties, sintering and fracture behavior of Ti (C,N) based cermets was investigated. Results show that the Ti (C,N) based cermets granules distribute in the matrix homogeneously. A nanoindentation study was performed on hard phase and binder phase in the matrix and granule. With the increase of granules content, sintering properties is worse. With the increase of granules content, transverse rupture strength (TRS) and relative density decrease gradually, while the hardness has an opposite trend. The fracture toughness increases firstly with increasing granule, and then decreases with the further increase of granules. Higher fracture toughness of the cermets is mainly owing to the crack branch and higher fracture energy of coarse granule.

Abstract: Hexagonal crystal system materials have very important applications in modern society. Dielectric constant tensor of hexagonal crystal system materials is simplified only by the formula in a hexagonal coordinate system, not by the formula often seen in current Chinese solid state physics textbooks. Meanwhile, the equivalence of hexagonal coordinate system and rectangular coordinate system is presented in the paper.

Abstract: This novel research work addresses the physical properties of Lead titanate (PT), PbTiO3 sample with additives. The modification of this sample was carried out by adding calcium in proportion of 5 to 15mol%. The samples in bulk form were synthesized by utilizing traditional method of solid state synthesis. The properties like structural analysis, and grain size determination were studied for the PbTiO3 sample & for the calcium modified lead titanate (PCT). The phase identification, structural characterizations and microstructural analysis hasanalyzed in this manuscript.

Abstract: Automobile exhaust is one of the sources of PM2.5, which can merely be catalytically decomposed by a "post-treatment" three-way catalytic device at present. Afront-treatment device based on rare earth-alumina nanocomposite in gasoline was innovatively introduced. nanoalumina and rare earth elements are function as the backbone and carrier, respectively. Microscopic molecular assembly and catalytic mechanism were studied to synthesize metastable ordered mesoporous with high degree of aggregation. Mesh filter of rare earth-alumina nanocatalytic composite with self-sustained release function is formed by sintering, which can be solidified in an automotive air intake system. Results show that rare earth-aluminum nanocomposite contributes to catalytic combustion and makes combustion more complete. Moreover, it has a better effect of reducing PM2.5 than a "post-treatment" device in terms of catalytic effect.

Abstract: 2116# Rosin Modified Phenolic Resin is synthesized by means of one-step process taking calcium hydroxide as catalyst and Rosin, Bisphenol A, solid formaldehyde and glycerol as main raw materials. The formulation and process are improved and characterized. The result shows that it satisfies technical performance indicators. And, it is preliminarily applied to ink. This resin is expected to be applied to printing ink and coating industry.

Abstract: This work studied the morphology, mechanical and thermal properties of poly (lactic acid) (PLA)/ethylene-octene copolymer (EOC) (80/20) blends with different organoclay types. Herein, EOC was introduced to toughening PLA by melt blending and organoclay was used to improve compatibility and tensile properties of the blends. The two organoclay types were nanoclay surface modified with aminopropyltriethoxysilane 0.5-5 wt% and octadecylamine 15-35% (Clay-ASO) and nanoclay surface modified with dimethyl dialkyl (C14-C18) amine 35-45 wt% (Clay-DDA). The organoclay contents were 3, 5 and 7 phr. Scanning electron microscope (SEM) observation results revealed PLA/EOC blends demonstrated a two-phase separation of dispersed EOC phase and PLA matrix phase. The addition of organoclay significantly improved the compatibility between PLA and EOC phases due to EOC droplet size decreased dominantly in PLA matrix, so organoclay could act as an effective compatibilizer. The incorporation of organoclay increased significantly tensile strength of PLA/EOC/organoclay composites while Young’s modulus increased with 5 phr of organoclay. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-ASO in the blends could improve the thermal stability of the PLA/EOC blends.

Abstract: In order to improve chemical mechanical polishing (CMP) efficiency and accuracy in the fabrication of planar optics, CMP models and machine tools have been developed. A three-dimensional contour map of the surface of the polishing plate was established by measuring the runout error of several circles on the polishing plate. Based on the Preston equation and the three-dimensional contour map, a CMP model that simulates material removal at any point on the work piece is proposed. This model shows that higher motion accuracy can improve efficiency and accuracy. Then, based on this point of view, a new CMP machine tool was designed, and the ultra-precision gas static pressure guide rail and turntable and Siemens 840Dsl numerical control system were applied to the new CMP machine tool. In order to validate the new machine, a series of testing and processing experiments were carried out. The straightness error of the gas static pressure guide rail can be less than 1.1 μm. The axial runout error of the gas turntable can be less than ±0.4 μm. The surface profile of the experimental workpiece can be less than 0.01λ, and the processing efficiency of the new CMP machine can reach 4 times of the processing efficiency of the conventional CMP machine. In addition, the repeatability and stability of the CMP process is improved on new machines.

Abstract: YC-1 booster (96.5% RDX, 3% F2641 and 0.5% graphite) was selected as the research object. Accelerated aging of YC-1 was carried out by 71°C thermal aging tests. The size changes of samples before and after thermal aging were measured. The initiation ability and shock sensitivity of the samples before and after accelerated aging were tested by steel compression test and SSGT small gap test. Through the establishment of equal proportion impact dynamics calculation model, the propagation law of shock wave generated by the explosion of A-= 9 \* ROMANIX-= 1 \* ROMANI was calculated. Test and calculation results show that: The diameter and height of samples increase with the increase of aging time. There was no significant change in the initiation ability of the samples, and the shock wave sensitivity increases first and then decreases with the increase of thermal aging time. The critical thickness of the gap corresponding to the samples aged 0 day, 4days, 19 days, 38 days and 76 days was 6.9mm, 7.0mm, 7.5mm, 8.1mm and 7.8mm, respectively. The corresponding shock wave pressure (without considering the interface reflection) in the gap was 2.91GPa, 2.85 GPa, 2.60 GPa, 2.40 GPa and 2.50 GPa respectively.