Applied Mechanics and Materials Vols. 271-272

Abstract: Aiming to get appropriate residual compressive stress distribution on machined surface just in the machining process, the technique of prestressed cutting is applied for nickel-based superalloy shafts. This article studies theoretically and experimentally the effect of prestress on the residual stress in the machined surface layer. Prestressed turning tests under the conditions of different prestress, cutting speed, depth of cut and feed rate were carried out, residual stresses were determined via an X-ray diffraction technique. Theoretical result demonstrates that higher prestress leads to more prominent residual compressive stress and validated by experiments, meanwhile measured residual stress profiles indicate that lower cutting speed and lower feed rate lead to more remarkable compressive stress state, contrarily depth of cut shows relatively indistinctive effect.

Abstract: Based on TEOS system and sol-gel process, together with catalysts, Antireflective coating films prepared by sol—gel on glass substrate have been processed by rapid thermal annealing (RTA). the refractive index and thinkness of SiO2 film is exactly controlled. The films are characterized by ellipsometer and SEM respectively. The quantum states in these processions are found and discussed.

Abstract: Based on TEOS system and sol-gel process, together with catalysts, Antireflective coating films prepared by sol—gel on glass substrate have been processed by furnace thermal annealing (FA). the refractive index and thinkness of SiO2 film is exactly controlled. The films are characterized by ellipsometer and SEM respectively. The effect of different temperatures in these processions are found and discussed

Abstract: Zirconium dioxide (ZrO2) nanocrystals were prepared by the microwave-assisted ionic liquid method using an ionic liquid of 1-n-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF4). The X-ray diffraction (XRD) patterns indicated that the crystal structure was monoclinic. The morphology of ZrO2 nanocrystals was characterized by field emission scanning electron microscopy (FESEM) and transimission electron microscopy (TEM), which showed uniform ZrO2 nanoparticles without aggregation. Thermogravimetry (TG) and Fourier transform infrared spectrometer (FTIR) curves confirmed the adsorption of organic compounds on the surface of ZrO2.

Abstract: This text introduced the research results of carbon fiber reinforced concrete beams and columns, and a brief description was presented about the influence of freeze-thaw cycles of carbon fiber reinforced concrete. Based on the experiment and related documents, studies the effects of the different dosage and different lengths of short carbon fiber on the compressive strength of concrete cube test. The results of experiment show the optimum dosage of carbon fiber is 0.24%.The improved compressive strength of carbon fiber reinforced concrete was particularly remarkable. The compressive strength could have a downward trend with the dosage increase. When the lengths of short carbon fiber is 10mm, compared to plain concrete, compressive strength increased 17.7%, and then the compressive strength could have a downward trend with the length increase. When the length of short carbon fiber is 50mm, compressive strength decreased 3%.

Abstract: Polycrystalline α-HgI2 films have been grown on TFT substrates using hot-wall vapor phase deposition (HWPVD) with the different growth times. The influence of different growth times (1 hour, 2 hours, 3 hours, 4 hours) on the structural and electrical properties of the polycrystalline α-HgI2 films is investigated. Metallurgical microscope, scan electron microscopes (SEM) and X-ray diffraction (XRD) characterization and the electric transport properties were investigated by the I-V characteristics. The polycrystalline α-HgI2 films growth by 3 hours show more better performance than others. So we use it preparation a detector.Finally, capacitance frequency characteristics analysis showed the detector have good performance.

Abstract: According to the hammer crusher working condition, a kind of dual liquid bimetal composite casting hammer was developed. Its service life is three times than that of high manganese steel. It improves the wear resistance and increases production efficiency significantly, and is welcomed by user deeply.

Abstract: The main purpose of this research is to optimise the injections moulding parameters in processing of thermoplastics samples made from Polypropylene (PP)-Clay with the fraction of 95% PP and 5% Clay, through Design of Experiment -Taguchi Method. The selection of defects or responses that need to be controlled for these thin layer products were warpage and shrinkage. The parameters that were taken into consideration were packing pressure; melt temperature, screw speed and filling time. In this research, the L934 orthogonal from Taguchi Method was chosen as the experiment setup. According to the results, 170°C of melt temperature, 80% of packing pressure, 70% of screw speed and 3 seconds of filling time gave minimum shrinkage of 3.45%. As for the warpage results, the best parameters combinations are 170°C of melt temperature, 70% of packing pressure, 70% of screw speed and 2 seconds of filling time. The Analysis of Variance for warpage shows that screw speed was the most significant factor with 41.83% contribution. As for shrinkage, the most influential factor was packing pressure with 98.48% contribution. Two factors have been pooled which are screw speed and filling time. Based on these findings, it is concluded that by controlling the optimum parameter setting, the best quality of desired product can be easily achieved and maintain through the in process production.

Abstract: Flammable liquid storage tanks could collapse easily and cause the accident spread rapidly in the high-temperature environment of pool fire, because pressure in the tank rises and the yield strength of wall decrease.So it is great significance to study the development of wall material under high temperature for the safety of flammable liquids tank farm. Taking 1,2- dichloropropane storage tank for example, based on the methods of heat transfer and numerical simulation, the mathematical model for thermal response of wall material 16MnR steel is builded to analyse the mechanical response of 16MnR steel under pool fire. When a pool fire of single tank took place in tank farm, the 1,2-dichloropropane was heated and gasitied that cause pressurizing, while the mechanical property of 16MnR steel weakened. By the finished model, this paper calculated the fail time of wall is 28.6min;failpoint of pressure is 2.065MPa;failpoint of temperature is 245°C,while temperature on heating surface of wall is 700-800 °C

Abstract: A nanolayer WN/TiN coating was grown using an industrial-scale four-target reactive sputtering system. Effects of heat treatment on fundamental properties and wear performance of the nanolayer coating were studied. For comparison, a single layer TiN was used as a reference. Characterization was carried out using a nano hardness tester, GDOES, XRD and SEM. Wear performance was evaluated using an SRV® wear tester. It was found that the as-deposited nanolayer WN/TiN coating showed relatively high nano hardness and wear resistance as compared with the single layer TiN. The heat treatment resulted in performance degradation of the nanolayer coating. After 600 °C heat-treatment, the nanolayer coating showed very poor mechanical performance.