Key Engineering Materials Vol. 863

Abstract: The demand for vegetable consumption is essential issue to serve citizens. Excessive protective chemical elimination which is applied advanced solutions brings high effects being investigated by domestic and international scientists. In this report, research team conducted and designed the vegetable washing machine integrated with the ultrasonic power and Ozone microbubbles to wash out plentiful protective chemicals attaching to surfaces of leafy vegetables. Followingly, using Taguchi method for four kinds of vegetables including salad, water spinach, Chinese cabbage, and mustard greens verifies the effectiveness of solutions. Vegetable samples are treated soaking pool making ultrasonic wave and Ozone microbubbles raging from 1.0ppm to 2.0ppm. The practical results demonstrated that the method using the ultrasonic power and Ozone microbubbles has high effects on eradicating protective chemical on leafy vegetables.

Abstract: This study presents conducted heat simulations and experimental jointing flat-plate of aluminum alloy 6061 and SUS 304. Temperature is simulated by the COMSOL software in three states: (1) Preheat the Friction Stir Welding (FSW) by TIG welding, (2) Thermal contact resistance between Aluminium and steel, and (3) The welding process using stiring friction is simulated. The simulations intended to predicting the temperature which is used for preheat and welding process to ensuring the required solid-state welding. The temperature is also determined and checked by a thermal imager comparing with simulation results. Besides, the results of tensile strength is carried out. The Box - Behnken method is used to identify the relationship between the welding parameters (rotation, speed and offset), temperature and tensile strength. The maximum tensile strength is 77% compared to the strength of aluminum alloy. The optimal set of parameters for the process is n = 676 rpm, v = 46 mm / min and x = 0.6 mm. The optimizing welding parameters to achieving good quality of welding process are described. SEM images to determine some properties of welding materials. This is also the basis for initial research to identify some defects in welding of two different materials (IMC thickness and interconnected pores) and the cause of these defects.

Abstract: In this paper, an induction heating system was applied to the heating stage in the injection molding process. Through simulation and experiment, the heating process was estimated by the temperature distribution and the heating rate. In the simulation, the mold temperature was increased from 30°C to 180°C in 9 s. Therefore, the heating rate was higher than 16°C/s, which represents a positive result in the field of mold heating. Additionally, the temperature distribution revealed that the higher temperature is concentrated on the gate area, while the outside of the mold cavity is at a lower temperature. The same parameters were applied to both the experiment and the simulation, and the results were in good agreement.

Abstract: 3D printing is a promising digital manufacturing technique that manufactures product parts in a layer fashion. Fused deposition modeling (FDM) is a widely used 3D printing technique that produces components by heating, extruding, and depositing the filaments of thermoplastic polymers. Meanwhile, the properties of FDM-produced parts are significantly influenced by process parameters. These process parameters have different advantages that need to be investigated. This paper examines the effect of some process parameters on the tensile properties of some components produced using FDM technique. The study is performed on polylactic acid (PLA) material, using full factorial experimental design. Furthermore, three process parameter—material, infill density, and infill pattern—are considered. The results indicate that only the infill pattern significantly influences the tensile properties of the model.