Applied Mechanics and Materials Vols. 271-272

Abstract: We report the effects surface treatment and annealing had on the properties of InN layers grown using metal organic chemical vapor deposition (MOCVD). The number of defects due to N vacancies decreased significantly with increasing annealing temperature. However, when the annealing temperature reached 700°C, the crystalline grain became larger on the film surfaces. Annealing at an appropriate temperature improved the crystalline quality and the electrical properties of the InN films. However, when the annealing temperature was too high, InN oxidized and even dissociated.

Abstract: A novel form-stable capric acid/organophilic montmorillonite composite for thermal energy storage is developed in this study. The morphology and thermal properties were determined by scanning electron microscope(SEM), polarized optical microscope(POM), differential scanning calorimetry(DSC) and thermogravimetric analyzer(TGA). The DSC results showed that the on-set temperature of the sample with 40% wt CA was closed to 29°C, the latent heat was 35.8 J/g at 56 kPa and 51.5 J/g at 0 kPa, while the on-set temperature of sample with 60% CA was also 29°C, the latent heat was 79.7 J/g at 56 kPa and 80.8 J/g at 0 kPa. TG investigations revealed that the composites had excellent thermal stability above their working temperature ranges. The POM images exhibited phase behaviors of composites to confirm leakage, and the samples with 20% and 40% CA showed good thermal properties. In addition, SEM images presented the microstructure of all the samples. All of the conclusions indicated that sample with 40% wt CA was a better candidate for novel form-stable CA/OMMT composite for low-temperature thermal energy storage applications.

Abstract: Electrolytic manganese industry production process generates serious environmental pollution and ecological problems. The wastewater treatment produced in the electrolytic manganese production has become a research hotspot in the fields of environment protection .In recent years, electrolytic manganese wastewater treatment focuses on various chemical processing methods and application of some technologies, there is little research on automation wastewater treatment equipment. In this paper, an automated processing system of electrolytic manganese wastewater is designed to meet the requirement of wastewater treatment and resource utilization, the equipment selects ion exchange method to dispose of wastewater manganese-containing and chromium-containing ion. The programmable logic controllers are used as the main controller, and configuration software is chosen as upper computer monitoring. The control system can efficiently implement ion exchange, regeneration, remote surveillance and other functions. This field operation shows that automated treatment equipment can automatically solve problem of electrolytic manganese wastewater treatment and resource utilization, and improve electrolytic manganese industry wastewater automation processing level．

Abstract: In this paper, considering an isotropic rheological law of the sheet material and the power law relationship between the stress and the plastic strain, the Erichsen test is used to identify the material constants of AA5083 aluminium alloy coupling experimental tests results with numerical ones obtained by using the finite element method. The function which is minimized by inverse analysis includes simultaneously the load-displacement curve of the punch, the normalized thickness measured at the bulge apex and the distance measured between the thinnest area of the metal sheet and the inner surface of the blankholder.

Abstract: This work provides a novel idea of fabricating MnZn bulk ferrite materials. MnZn ferrite powders with a composition of Zn0.8Mn0.2Fe2O4 (wt%) are sintered to form cylindrical bulk ferrite with diameters of 1.0mm, and heights of 1.0mm under multi-physical field coupling with Gleeble-1500D thermal simulation instrument. The results show that sintered ferrite has a spinel structure, and that some magnetic properties like maximum energy product and remanence of the Multi-physical Field Coupling sintered sample are better than that obtained by conventional sintering. Densification process and solid phase reaction are promoted by alternating magnetic field and high frequency wave generated by AC current.

Abstract: In order to improve the anti-mildew property of modified bamboo with photocatalyst, it used TiO2 which is one of the typical photocatalyst as the main study object to discussed the kinetics of immersion of photocatalyst in bamboo. The results show that immersion of TiO2 in bamboo can be divided into three stages, starting with the rapid immersion, the slow immersion in the middle stage, and the stable immersion in the later stage. In the stable stage, only little TiO2 immerse bamboo. The immersion rate is faster at higher temperature to take less time to reach equilibrium. By establishing the kinetic models, the reaction of immersion of photocatalyst can be regarded as the first order reaction with reaction order of 0.97, the reaction rate constant increases with increasing temperature, the activation energy is 5663.133J/mol, and the pre-exponential factor is 20.47h-1.

Abstract: Using high-pressure sealed microwave heating method, the WC-Co based cemented carbide samples were digested completely by nitric acid and phosphoric acid (VHNO3: VH3PO4 = 5:1). Then the digestion solution was diluted with water to a constant volume, and directly using inductively coupled plasma atomic emission spectrometry (ICP-OES) determination of the content of 0.005 to 10% Co and 0.005 ~ 1% of Fe, Nb, Ta, V, Cr, Mo and Ni. This paper examine the best digestion conditions, including reagent composition, ratio, and microwave control parameters, etc., then establish a set of microwave digestion and by complex reactions with inorganic reagents to stabilize the high tungsten matrix digestion method, in order to quickly and completely digest the tungsten-cobalt-based samples and avoid the generation of tungsten acid precipitation resulting in the loss of some of the analyte and impact of organic complex agents on the spectral determination. The results showed that: the control parameters of using 5 min to heat the sample to 130 °C and keep for 5 min, then heated to 190 °C in 5 min and keep for 15 min is better to maintain the digestion. By optimizing elemental analysis line, ICP measurement parameters and matrix matching and synchronization of background correction method, the high tungsten matrix effects and spectral interference are eliminated; ensure the detection performance of the method. Background equivalent concentration of 5μg/L (Nb) ~ 18μg/L (Fe), elements of the detection limit of 4μg/L (Nb) ~ 13μg/L (Fe), which used for the determination of impurities in the alloy or elements with the results is RSD <3%, recovery 97.0% ~ 103.5% corresponding with the national standard examination method.

Abstract: In order to alleviate thermal stress of piston head, the causes of thermal stress are studied. The original piston is modified from the perspective of easing strain concentration. The thermal stress and strain fields of the original and modified pistons are analyzed with FEM. Comparison of the analysis results shows that analyzing strain concentration is an efficient way to find out the fundamental causes of high thermal stress of piston head. Thus viable approaches are proposed to solve the problem.

Abstract: The purpose of this paper is to demonstrate the influence of atomizer disc shape and size on the characteristics of zinc metal powder produced by centrifugal atomization. Two types of atomizer disc were employed, the flat disc and the cup-shaped disc with diameters of 30 and 50 mm for each type. The atomization was carried out in ambient air atmosphere, at pouring melt temperature of 550°C. The molten zinc was fed by gravity through a 1.0 mm nozzle with melt flow rate of approximately 50 kg/hr onto the atomizer disc spinning with a speed of 30,000 rpm. It was found that, the median particle size of zinc metal powder was decreased with increasing atomizer disc size. The cup-shaped disc gave better powder production with smaller particle median size and higher production yield. SEM images revealed that most zinc metal particles were irregular, ligament and elongated flakes. The oxygen in air might inhibit the spheroidization of melt droplet during solidification.

Abstract: This article describes optimization mathematical model of metal rubber buffer on artillery. In this paper, motion equation of new metal rubber buffer on artillery, stiffness model of the ring spring, constitutive relation of metal rubber, and mathematical model of friction block are constructed. According to the technical requirements of buffer, optimization variables, constraints, and object function are identified. Then optimization mathematical model is established.