Key Engineering Materials Vol. 856

Abstract: Nowadays, the industry has been growing interest in lightweight material for automotive and cookware manufacturing. The formability of sheet material is an important issue in these industries. The wrinkling behavior is one of the most failure in sheet metal forming and is often occurred in deep drawing process in cookware manufacturing. In this work, the developed wrinkling limit curves (WLCs) using experimental and numerical simulation of a modified Yoshida buckling test were precisely used to predict the wrinkling behavior of rectangular cup deep drawing for aluminum alloy sheets grade AA5054-O and AA5052-H32. The Industrial parts, the rectangular cup deep drawing was firstly performed for both investigated aluminum sheets for obtaining the wrinkling initiation on the side wall area of deep drawing parts. Subsequently, the experimental formed parts were carefully measured the draw-in of deformed blank sheets and drawing depth to validate the finite element (FE) model. Then, the FE simulation of the corresponding drawing tests were calculated, by which were implemented with the Hill’48 yield criterion and Swift hardening law to descript anisotropic plastic deformation. As a result, the local principle Major and Minor principle strains of observed wrinkle areas were gathered in the side wall area of the rectangular cup deep drawing test. Finally, the developed WLCs of aluminum alloy sheets were applied to predict the wrinkling formation of the formed deep drawing parts. Comparatively, the influence of different aluminum alloy grades on the WLCs and wrinkling behavior were explicitly investigated.

Abstract: Barkhausen noise (BHN) is a technique that can be used to evaluate properties of ferromagnetic materials; case depth, coating depth, residual stress, grinding burnt damage, and hardness of a metallic material. The commercial BHN measuring devices commonly used are relatively expensive. Therefore, the steel industries in Thailand hardly use in their production process. A cost-effective measuring system based on BHN was developed in this research. The developed machine was tested by measuring the hardness of different steels. The hardness measured by the developed BHN system was validated with the hardness measured by the Vickers hardness test. It can be concluded that this proposed measuring machine can estimate the hardness of steels with accuracy of 96.76 percent on average (in hardness rage of 150 – 800 HV). This development can also be applied to measure other properties if the appropriate operating parameters of the machine are changed and calibrated with reliable standards.

Abstract: Understanding and predicting relationships between laser welding process parameters, such as laser power and welding speed, and molten pool have been studied widely in order to critically control and improve laser welding. The laser welding processes are difficult to monitor in real time because of high temperature and rapid heating characteristics. In this study, infrared camera was set to collect data and provide real time monitoring system to determine the molten pool characteristics and weld quality. This study carried out a laser welding of SS400 low carbon steel and analyzed real-time image of the welding process to determine the average temperature of molten pool and calculate the size of molten pool. By varying the laser power and the welding speed, the infrared camera and imaging processing technique can monitor change of molten pool temperature in a range of 1000 C to 15000 C with about 1% temperature fluctuation. In addition, the size of molten pool can be calculated from the temperature profile of the welding zone. The calculated molten pool size was about 95% accurate compared to the measured size from microscope imaging.

Abstract: Solution styrene-butadiene rubber (SSBR) reinforced by hybrid fillers of carbon black (CB) and silica (PSi) was prepared with various CB/PSi ratios. Rheological and mechanical properties of rubber compounds and vulcanisates were investigated. Results of compounds demonstrate that, with increasing CB fraction, increases in the magnitude of the Payne effect and Mooney viscosity were found. On the contrary, with increased loading of PSi, increases in optimum cure time (t_c90) and cure torque difference were evidenced. The results suggest superiority in filler dispersion level and cure efficiency in the systems filled with high PSi fraction due to the presence of Bis [3-(triethoxysilyl) propyl] tetrasulphide (TESPT or Si-69) as a silane coupling agent. As for vulcanisate properties, the systems with increased PSi fraction exhibit enhancement in mechanical strength and elastic contribution, which are in good agreement with rubber compound properties. Also, the decrease in loss factor at 60 °C was observed with increasing PSi fraction, suggesting the desirable reduction in rolling resistance of tyre tread.

Abstract: A lightweight structure has been often mentioned in the automotive industry due to the increasing cost of energy as well as environmental legislation. Multi-material design is applied to reduce the weight of a car body. To join dissimilar sheet materials, it is quite difficult to achieve by welding processes. A flat-clinching process is one of the mechanical joining processes, which have join-ability of dissimilar sheet materials by plastic deformation. The purpose of this paper was to study the clinch-ability to join AA1100-to-AA1100 aluminum, AISI1010-to-AISI1010 steel, and AISI1010 steel-to-AA1100 aluminum sheets. Furthermore, the effect of both blank holder force (BHF) and edge radius (BHR) in the flat-clinching process on a joining strength was investigated. A shear strength test was conducted to examine the joining strength. The results show that the flat-clinching process can be successfully applied to join the similar sheet materials with the formation of interlocking. However, to achieve the joint of the dissimilar sheet materials, the AISI1010 steel sheet must be on the punch side. Also, both the BHF and the BHR significantly influent on the joining strength.

Abstract: This research investigates the application of three sulfonic resins (Amberlyst-15, Dowex-G26 and Dowex Monosphere-650C) as acid heterogeneous catalysts for oxidation reaction of furfural with hydrogen peroxide solution. The reaction was carried out in a batch reactor with varied reaction time (4-24 h) and temperature (70-90 °C). The sulfonic resins were characterized as to their structure and chemical composition by N₂ adsorption-desorption isotherm, Fourier transformed-infrared (FTIR) spectroscopy, acid-base titration, and scanning electron microscopy (SEM). The results showed that all three resins gave similar catalytic activities. The highest yield of succinic acid was 75.7 % in the presence of Dowex-G26 catalyst at 80 °C and 4 h.

Abstract: Compatibility investigation was performed between magnesium stearate and acidic drug compounds (ibuprofen, indomethacin and valproic acid) and acidic pharmaceutical excipients (lactic acid and citric acid) using differential scanning calorimetry (DSC). DSC study indicated the possible incompatibility for the mixture between magnesium stearate and any compounds. Alteration in DSC thermogram was found in all mixtures. The eutectic phenomenon was found in the powder mixture of magnesium stearate and ibuprofen. In addition, the presence of melting endothermic peak of stearic acid in other powder mixtures except the mixture of magnesium stearate and indomethacin indicating breakage of salt form of magnesium stearate. This alteration could relate to the influence on physicochemical properties of drug compounds and pharmaceutical excipients which powder x-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) should be further analyzed to confirm the interactions between compounds.

Abstract: Biogenatic nanosilica was synthesized by sol-gel method from rice husk ash. The batch reactor was designed to scaling-up from laboratory scale approximately 5 g to approximately 300 g of the feed raw materials. The synthesized silica products from lab-scale vessel and scaling up designed batch reactor were compared with percent yield and nanoparticle size. The particles of nanosilica from both scale productions were characterized by X-ray Fluorescence (XRF), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). The size and size distribution of nanoparticles were estimated by ImageJ software in 100 points from SEM images. The synthesized nanosilica particles from laboratory vessel and designed reactor were the same of % yield production, components, physical structure, silica purity, and nanoparticle size. Moreover, the commercial nanosilica was analyzed for comparison.

Abstract: Emulsification of water and fuel oil emulsion was experimentally investigated. The water-in-oil emulsion was produced with ultrasonic mixer and phase inversion concentration using a mixture of Span80 and Tween80 as emulsifiers. The emulsion was characterized by water droplet size, distribution and visual observation of microscopy photographs. Water in fuel oil emulsion prepared by phase inversion concentration was found to be similar to that prepared by the ultrasonic mixer in term of average droplet size and distribution

Abstract: Ion removal is a long problem on natural freshwater resources. In order to modify the adsorption performance to remove ions from standard iron solution, natural zeolite and natural perlite were treated with deionized water (DI water) as D-zeolite and D-perlite. And, 1M sulphuric acid (H₂SO₄) was used to treat the adsorbent as H-zeolite and H-perlite. The capability of ion removal was preliminarily investigated from the reduction of iron in solution by X-ray fluorescence spectrometer. The result showed that treatment of adsorbents with DI water was more capability than 1M H₂SO₄ solution.