Key Engineering Materials Vol. 877

Abstract: The effect of the addition of epoxysilane-treated wollastonite (ETW) to the mechanical and thermal properties of 3D-printed acrylonitrile butadiene styrene (ABS) via fused deposition modeling (FDM) was investigated. The loading of ETW was varied at 1, 3, and 5wt%. The 3D-printed composites were evaluated by scanning electron microscopy (SEM) tensile test, shore D hardness, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of ETW increases the tensile strength, elastic modulus, and toughness of ABS by up to 46.6, 56.2, and 53.7 %, respectively. The shore D hardness increases with increasing ETW. Morphological analysis show that this improvement in mechanical properties is a result of the high aspect ratio of the fillers, the uniform dispersion of ETW in the ABS matrix, and the orientation of ETW particles toward the direction of tensile stress. The glass transition temperature (T_g) of the composites increases and the onset of degradation slightly shifted to higher temperature with an increase in filler loading. The addition of ETW to ABS matrix in FDM 3D printing improved the mechanical and thermal properties of ABS.

Abstract: Epoxysilane-treated muscovite (ETM) was used as reinforcing filler to 3D-printed acrylonitrile butadiene styrene (ABS) via fused deposition modeling (FDM). Its effects to the mechanical and thermal properties of ABS were investigated. ETM was loaded at 1, 3, and 5wt%. ABS/ETM composites were characterized via scanning electron microscopy (SEM), tensile test, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical reinforcement of ABS was observed for ABS/ETM composites loaded at 1 and 3 wt% wherein it was noted that the tensile strength and elastic modulus increased by up to 83.6% and 76.6%, respectively. Reinforcement was brought by interfacial adhesion of ETM with the ABS matrix. There was a sharp decline in mechanical properties for ABS/ETM composites loaded at 5wt% due to agglomeration of ETM in the matrix and discontinuities in the printed layers. The glass transition temperature (T_g) of ABS increased and the onset of its degradation shifted towards higher temperatures with the addition of ETM. It can be concluded that the addition of ETM to ABS for FDM 3D printing improved its mechanical and thermal properties.

Abstract: The purpose of this study is to investigate the forming characteristics of single-pass Metal Inert Gas (MIG) welding wire for multi-layer additive manufacturing parts. Influences of arc current, arc voltage, arc distances, welding speed, wire feed speed, temperatures and heat input on layer formation were analyzed. The deposition of material by MIG process is controlled by a robot (ABB) controller for constructing walls of rectangular box shape. The samples were measured with a microhardness testing and tensile testing onto the welded bead created by the additive manufacturing technique. It was found that the mechanical properties of microhardness values are between 151.70 to 155.80 HV and the tensile strength values are between 472.71 to 491.12 MPa according to transverse and longitudinal sections of the specimens.

Abstract: The manufacturing industries for automotive parts aim to develop technologies for reducing vehicle weight in order to decrease fuel consumption. However, passive safety function for drivers and passengers must not be impaired or should be even improved. Therefore, advanced high strength steel sheet plays more and more important role in designing automotive components. Nowadays, prediction of formability for sheet metal stamping has high capability more than the past. The major challenge is springback prediction. Moreover, it assists in the tooling design to correctly compensate for springback. Especially in automotive production, springback effects have been generally exhibited distinct after forming process of the high strength steel sheets. The springback effect occurred in the deformed state of metal parts must be taken into account by designing any sheet metal panels. Then, the purpose of the present research is to investigate the springback phenomenon of an automotive part named Reinforcement Rocker RL made from an advanced high strength steel grade JAC780Y, after stamping. In addition, the tools design has been carried out. Finite Element (FE) program known as DYNAFORM (based on LS-DYNA solver), has been applied to analyze and improve the springback effect on such forming part. An anisotropic material model according to type 36 (MAT_036 3-PARAMETER_BARAT) was applied. The results obtained from simulations were compared with required parts in each section. Then, the die surface from compensation in 2nd step forming was modified to use. Finally, the simulation part was verified with the real stamping part. It was found that the finite element simulation showed high capability for prediction and compensation of springback in high strength steel sheets forming.

Abstract: In order to prevent distortion caused by heat which affects the material deformation, the properties controlled are required. The properties changes and the placement of the mounting position will effect the weld strength that causes cracks and broken joints, therefore it affects the safety of machine construction. Thus, the objective of this paper is to control the shape of cross member backbone assembly by gas metal arc welding (GMAW). The welding is produced by an automatic robot Yaskawa-MA1440 type. In order to obtain the good quality of the result, the welding shape is controlled by a parameters combination of voltage, current, and speed. Yaskawa-MA1440 type is used as the automatic welding machine. The main material used is cold rolled steel coil sheet MJSC270D-OD with a thickness of 1.2 mm. In addition, to control the welding shape, the specified shape design standard is followed include travel speed, gas flow, welding direction, torch tip distance to the workpiece, torch angle and welding angle. The results of visual and dimensional were also examined in this research. Furthermore, the macrostructure i.e. leg length, fusion penetration, throat thickness have been analyzed and confirmed based on the standards used in the auto body vehicle part company. The appropriate parameters for the finest welding shape are defined at the horizontal position using an electric current of 120 A and the welding voltage of 18 V (± 1 V). Thus, the measurement control of macrostructure is defined as reference parameters for mass production of cross member backbone assembly.

Abstract: Metal oxide semiconductor has been widely used for breath analyzer applications. In this work, Acetone gas is the target gas as it an important breath marker for diabetes disease. Among the different p-type metal oxide nanostructures, Nickel oxide nanospheres are used as the sensing material as it is a promising candidate for Acetone sensing. The variation of resistance of the sensing material with the concentration of the target gas was analyzed. As Acetone is a reducing gas, the resistance of the sensing layer was found to increase when the sensing layer was exposed to the target gas. The simulation was done using COMSOL Multiphysics.

Abstract: A novel redox couple of metallic nickel (Ni) catalyst can become a great candidate of non-enzymatic detection. By taking advantage of fast electron transfer, Ni redox couples can be tailored as pseudo-enzyme in urea measurement. In this study, Ni catalyst on nitrogen doped carbon (Ni-NC) was synthesized and characterized morphological, elemental, and electrocatalytic properties in comparison to different configuration of pure nickel (Ni), Ni with carbon (Ni-C), and bare carbon electrode, assessed by cyclic voltammetry and differential pulse voltammetry. By examining various Ni redox couples in rapid electron transfer process, the prominent anodic and cathodic peaks of Ni²⁺/Ni³⁺ were applicable to detect urea in the detection range of 1-20 mM, with an excellent sensitivity and relative standard deviation of 1.634 μA.mM^-1 (R² of 0.989) and 4.89%, respectively. Therefore, Ni-NC can find practical applications for material sensing device toward non-enzymatic urea measurement.

Abstract: This study focused on the mechanical properties and ablation properties of liner insulation in rocket motors for improving rocket performance by means of tensile strength, elongation, ablation rate and density. The following parameters were varied: amount of zinc oxide, antimony trioxide and carbon black (N550). It was found that the insulation of the rocket motors with antimony trioxide and carbon black provided higher the elongation and ablation rate. Thus, it was able to endure more heat from hot gas in combustion chamber. The result suggests that use of antimony trioxide and carbon black as filler in liner insulation can improve the thermal insulators and case-bonded in rocket motor between the solid propellant and the rocket motor tube.

Abstract: Heusler alloys have been considered as one of the most promising thermoelectric materials for electrical power generation in a temperature range of 500–800 °C. Establishment of phase diagrams allows one to predict formation, equilibria, and stability of phases in of these ternary alloys. In this work we report on the simulation and investigation of phase diagram and phase equilibria in ternary Ti-Fe-Sb system which is of considerable interest for thermoelectric applications. The simulation was carried out using the CALPHAD method in Pandat software. The existence of the thermoelectric Heusler TiFe_1.5Sb phase was revealed in a temperature range from 970 to 1070 K. The equilibria between TiFe_1.5Sb and other phases were determined. The entropy of formation was calculated for the phases existing at 970, 1020 and 1070 K using a fitting approach. A narrow equilibrium region containing pure body centered cubic Fe and TiFe_1.5Sb was found.

Abstract: Kaolin beneficiation mining is one of the sectors in a supply chain of ceramic industries, supplying qualified raw materials for manufacturing high-quality ceramic products. However, substantially by-products are generated from the mining process. The abundance fraction of sand-wastes is generated by approximately 40% of kaolin material input, amounting to 172,200 tons/ year. The burden of the manufacturer is attempting to find out the way to solve this problem. The effort of this research is to utilize waste by-products (sand-wastes) from kaolin mining. The eco-friendly Non fired wall tiles are developed with the combination of sand-wastes, laterite soil, river sand, and Portland cement Type I. They have been compared with the Thai Industrial Standard (TIS 2508-2555). Results of the experiment show that the proposed wall tile can achieve the physical properties of TIS 2508-2555. Scanning Electron Microscope (SEM) has been studied to analyze the surface morphology of specimens. This can be summarized that 25% of sand-wastes can be utilized in wall tiles. In addition, energy-saving for non-firing products is achieved. Furthermore, energy-saving is also calculated and compared with fired wall tile which has similar properties.