Advanced Materials Research Vols. 875-877

Abstract: There is the higher fault probability under the bad work conditions of the rod pumping system.According to the failure of the sucker rod pumping installation, a comprehensive survey is carried out. There is many influence factors of deep well pump working downhole, not only influenced by the machine, wells, pumping equipment, but also by sand, wax, gas, water. Pump conditions can be diagnosed by surface dynamometer card, surface dynamometer card is the first-hand information collected in pumping well of oilfields. By analyze the Characteristics of the different fault dynamometer, Lay the foundation for the further fault diagnosis and prediction. The different pattern of the different dynamometer is important.

Abstract: Entrained flow gasification technology has been attracted by gasifier researchers and companies for its wide-ranging feedstock adaptability and commercial scale availability. The optimization of the entrained flow gasifier is the critical thing for the development of entrained flow gasification technology. This paper presented a three-dimensional computational fluid dynamic (CFD) simulation for a better understanding of the cold condition flow characteristic in an entrained flow gasifier. The spraying angle, diameter and injection velocity of nozzles were found to observably affect the velocity distribution and mixing condition in the entrained flow gasifier. The numerical results could provide useful information for further research on the particle track and gasification reaction and an effective process for optimizing the gasifier and nozzle.

Abstract: Modes supported in air-core Bragg fibers with infinite number of H/L(high/low) layers are modeled and simulated which provide a solid foundation for the analysis of modes supported in air-core Bragg fibers with finite number of H/L layers. Three types of modes supported in Bragg fibers with a finite number of H/L layers are well defined and divided into branches in the mode spectrum. The three types of modes can be identified as quasi-guided modes, leaky modes and PML modes and their different characteristics are shown by the corresponding field patterns.

Abstract: The purpose of this research is to fabricate the hip and pelvis part for designing the acetabular implant by using Fused Deposition Modeling (FDM) technique. The methodology of this research is begin by converting the 2D image of CT into 3D image through Invesalius 3.0 software. Then the 3D image is converted to .stl format and exported to FDM machine for fabrication purpose. The finish prototype of 3D biomodel replica is evaluated in order to define the problem face by the patient. Also, the dimensional accuracy is measured between 3D replica model and 3D virtual model. Based on the result of 3D biomodel, the ball joint of the femur on the right side is dislocating from its original position because of the fracture occur on acetabular socket. The implant for acetabular fracture is design by using CATIA software and the design must ensure to be fit with the fracture area. Therefore, this study has contributed to medical area especially in Malaysia in improving patient specific preoperative planning and giving better visualization information of the fracture.

Abstract: We aim to develop a new fatigue model valid for quasi-brittle materials like concrete, which properties have considerably larger standard deviation than metals. Having this in mind, we fit the measured strength data with a three-parameter Weibull cumulative distribution function and in turn take it as the initial distribution for an asymptotic fatigue model in concrete. We also take into account the observed influence of frequency and stress ratio on the fatigue life in concrete, both plain and reinforced with fibers. The developed model is validated against fatigue tests in compression on cubic specimens for different stress ratios and loading frequencies. The secondary strain rate is also found to be correlational with the number of cycles to failure.

Abstract: A kind of carbon fiber (CF) reinforced conductive composite material with graphite powders and polyphenylene sulfide (PPS) resin powders were fabricated by the hot-pressure molding method. The influence of graphite content and CF addition on the conductivity, flexural strength and density of the composite were investigated. Took into account the performance requirement of the bipolar plate of PEMFC and economic aspect, the suitable conditions for the fabrication of bipolar plate were found: the proportion of graphite and PPS was 75/25 and the addition of CF was 2.5%(wt).

Abstract: The microstructure, microhardness and corrosion resistance of as-cast and as-annealed ZnAl15 alloys were investigated by OM, SEM, EDX and DSC techniques. It was found that microstructure of as-cast ZnAl15 alloy was primary dendrites and eutectic matrix. But Primary discontinuous precipitation of αs and βs phase occurred at room temperature. During homogenization treatment, discontinuous precipitation of αs and βs phase occurred completely and accompanied with emitting heat. The final microstructures of decomposed αs and βs phase in primary dendrites were fine and coarse lamellar structures respectively. The final microstructures of decomposed βs, which located at the edges of the αs phases or in eutectic matrix were that α phase distributed in η matrix. The microhardness of both primary dendrites and eutectic matrix in ZnAl15 alloys decreased after homogenization treatment due to the decomposition of supersaturated solid solutions. The result of accelerated corrosion test showed that homogenization treatment has a certain beneficial effect on the corrosion resistance of ZnAl15 alloy.

Abstract: Aluminium AC4B alloy is widely used in automotive industries for various components. However, when this alloy is used to produce motorcycle cylinder head by Low Pressure Die Casting (LPDC) process, high reject rate was often found due to shrinkage, porosity and misrun. Addition of grain refiner and modifier is an alternative for this problem, through the control of solidification process that results in grain refining and microstructure modification. This study was aimed to investigate the effect of combination of 0.02 wt. % Sr modifier with variation of Ti grain refiner on the characteristics of AC4B alloy and the reject rate of cylinder head components. The Ti grain refiner was varied 0.063, 0.083 and 0.108 wt. % Ti and added at the holding furnace prior to LPDC process. A series of test was conducted including hardness test from the thin and thick regions of the part, tensile test, fluidity test, vacuum test as well as observation of microstructure by using optical microscope and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-Ray Analysis (EDAX). The results showed that the higher the Ti content, the higher the hardness for both thin and thick areas, the lower the fluidity of the molten metal. At the maximum level of Ti of 0.108 wt. % and 0.02 wt. % Sr, the reject rate was significantly reduced from 3.59 % to 1.38 %.

Abstract: This paper introduces forming processing method by multiple spark electric sparks (EDM). This method can get more material removal rate, and reduce the power consumption.

Abstract: The Cr-Mn-Ni austenitic steel cast alloys containing 16 wt.-% chromium, 7 wt.-% manganese and 3 to 9 wt.-% nickel are used as matrix material to manufacture TRIP-Matrix-Composite containing MgO partially stabilised ZrO₂ ceramics. In the present work, these steel master alloys were atomised via a vacuum inert gas atomisation to provide fine grain sized metal powders for the assembling of TRIP-Matrix-Composite. The atomised steel powders where characterised according to their chemical composition and the d₅₀ mass median particle size determined by a laser diffraction analyses. The surface tension of the liquid steel alloys was experimentally investigated using the maximum bubble pressure (MBP) method. The reference austenitic steel alloy (AISI 304) has the highest surface tension and the highest mass median particle size compared to the Cr-Mn-Ni steel alloys, where d₅₀ values are lower due to lower surface tension values. Finally, it is concluded from the present investigation, that the d₅₀ size of the atomised steel powders decreases by a decrease of surface tension values for the liquid steel alloys.