Materials Science Forum Vol. 982

Abstract: The objective of this study was to develop protein bioplastics from fish waste using different types of plasticizers; polyethylene glycol, triethylene glycol and glycerol. Fish protein powders (head, skin, scales, viscera) were prepared from sardine byproduct (SBP), mackerel fillet powder (MFP) and mackerel byproduct powder (MBP). Protein content was characterized using proximate analysis and amino acids was determine using amino acid analysis. SBP was transform into bioplastics by using extrusion and compression moulding. The properties were characterized using thermo gravimetric analysis (TGA) and mechanical testing. Protein content in byproduct (SBP and MBP) were reasonable at approximately 40-60%. TGA result showed two stages of thermal decomposition starting at 230 °C. Below 230 °C, it was believed that protein denaturation occurred, involve structural or conformational changes from native structure without alteration of amino acid sequence. Further heating after 230 °C showed massive weight loss that lead to degradation. Mechanical properties was majorly influenced by plasticizers which improved the elongation at break properties. Glycerol was found to be the most effective plasticizer among those studied here, possibly because of its characteristics such as low molecular weight, high solubility in water, and large protein miscibility. The results obtained in this study showed that plasticizer types and concentration significantly improve film properties and enhances their suitability for single used of agriculture applications.

Abstract: The Fiber metal laminates (FMLs) combine the advantages of fiber-reinforced polymer properties, like stiffness and strength, with metallic alloys, like toughness and durability. These hybrid materials can unravel some problems in the industrial sector, particularly in aerospace, and advanced automotive industry. Still, there are significant challenges in the GLARE sheets forming process even for small drawing ratios, notably smaller and complex-shaped fiber metal laminate with low thickness. As a case study, a cylindrical GLARE cup was chosen. This shape with sharp bends and vertical geometrical features, still face many challenges and difficulties in the forming process. Numerical simulations have been used utilizing ABAQUS and compared with the experimental results in the Hydro-mechanical deep drawing to achieve good forming quality with higher depth. An extensive investigation of the effect of process variables has been done such as cavity pressure, blank holding force, and blank diameter. Also, their roles in wrinkles formation, tearing and thinning, and formability has been performed. Furthermore, the friction in two cases; cured, and semi-cured condition, has been considered. The results show that the application of cavity pressure within specified limits has a positive effect on the quality of the formed cup and leads to higher depths. The same conclusion for the blank holder, which has a positive impact on wrinkling elimination and friction reducing between the aluminum layers and the fiberglass. The result shows that the semi-cured condition of the GLARE has a good effect on wrinkling reduction, due to the uniform movement of the fiberglass inside the aluminum layers. Understanding these parameters and the GLARE forming behavior and have a good selection of these parameters can give the advantage to achieve smaller and more complex shapes with higher depth, particularly for mass production. Finally, this study can extend the industrial application areas of FMLs and GLARE parts.

Abstract: Fiber metal laminates (FMLs) are widely used in aerospace industry due to their unique high specific strength, fatigue resistance, corrosion resistance and other excellent characteristics. Thermosetting FMLs is generally used for forming large size parts and rarely used as raw material for producing small size and complex shape parts. This study attempts a methodology that stamping thermosetting FMLs to form cylinder shape parts before the curing process. The forming limit height of FMLs were analyzed by choosing different core materials, layup direction and skin layer thickness. And through the optimization of these variables, a better-quality part has been formed.

Abstract: 3D Printing in space has shown obvious advantages in several fields such as on-ground or in-situ manufacturing, space supplies, reducing spares and transportation, emergency response and promoting deep space exploration. This paper analyzes the application modes and technology development trend of 3D Printing in space. Based on the investigation of the current situation, technical plans and the potential development of 3D Printing in space, the article proposed a technical path suitable for the development of 3D printing in space.

Abstract: This paper presents a closed-form solution for the temperature prediction in selective laser melting (SLM). This solution is developed for the three-dimensional temperature prediction with consideration of heat input from a moving laser heat source, and heat loss from convection and radiation on the part top boundary. The consideration of heat transfer boundary condition and latent heat in the closed-form solution leads to an improvement on the understanding of thermal development and prediction accuracy in SLM, and thus the usefulness of the analytical model in the temperature prediction in real applications. A moving point heat source solution is used to calculate the temperature rise due to the heat input. A heat sink solution is used to calculate the temperature drop due to heat loss from convection and radiation on the part boundary. The heat sink solution is modified from a heat source solution with equivalent power due to heat loss from convection and radiation, and zero-moving velocity. The temperature solution is then constructed from the superposition of the linear heat source solution and linear heat sink solution. Latent heat is considered using a heat integration method. Ti-6Al-4V is chosen to test the presented model with the assumption of isotropic and homogeneous material. The predicted molten pool dimensions are compared to the documented values from the finite element method and experiments in the literature. The presented model has improved prediction accuracy and significantly higher computational efficiency compared to the finite element model.

Abstract: Nowadays, finite element method (FEM) has been widely used to forecast metal forming process, to analysis problems of workpiece, to decrease production cost, and to save time of die design. This work studied the use of FEM as a tool to design a hot forging die for producing an automotive part named Yoke Spline. The part was made from carbon steel grade S45CVL0. There are three processes to produce Yoke Spline, including the buster, rougher, and finisher processes. The objective of the study was to increase efficiency of production by 5%. To achieve this objective, it was necessary to design a new die in the buster process by using FEM to analyze the die size and shape. The new die must produce the workpieces without any defects. The defects regularly found in the forging workpieces are the dimension out of specification, the under filling, and the crack. The sizes of the buster upper die cover are the width and depth. The die width of 44.5, 46.5 and 49.5 millimeters and the die depth of 25, 28 and 31 millimeters were used in the hot forging simulation. From FEM simulation results, it was found that the die width of 46.5 millimeters and the die depth of 28 millimeters were the best to form workpieces without any defects. In summary, the simulation and experimental results were compatible.

Abstract: The effects of bismuth content on the microstructure, shear strength and thermal properties of Sn-0.7Cu-0.05Ni solder joints were investigated. Adding 2 wt% elemental Bi to Sn-0.7Cu-0.05Ni solder joints reduced peak temperature by about 6.7 °C, increased pasty range by 4.2 °C and raised undercooling by 3.1 °C. The microstructure of the interfacial layer between solder and Cu substrate was composed of (Cu,Ni)₆Sn₅ and (Cu,Ni)₃Sn intermetallic compounds (IMCs). The solder joint included a phase of SnBi and Cu₆Sn₅ IMCs. The addition of elemental Bi increased shear strength and suppressed the growth of IMCs in the interfacial layer of the solder joints.

Abstract: A cylindrical indenter was designed to simulate the roller and 304 stainless steel / Q235A carbon steel plate with different roughness were bonded together. The interfacial bonding behavior was investigated by SEM, ultrasonic “C” scanning detection and nanoindentation test. The result reveal that with the increase of contact pressure between interfaces, the atoms of dissimilar metals begin to diffuse across interfaces in some regions, then form island-like bonding regions, and eventually extend to the whole interface. There are no obvious cracks on the surface of stainless steel and carbon steel after deformation. The cold roll-bonding mechanism of stainless steel and carbon steel is that elements on both sides of the interface diffuse and form a shallow diffusion layer under pressure to ensure the joint strength, and the joint bonding strength is greater than the strength of carbon steel matrix. In addition, the surface morphology of base metal has a great influence on the interfacial bonding quality. The higher surface roughness values increases the hardening degree of rough peak, which makes real contact area difficult to increase and reduce the interfacial bonding quality.

Abstract: In Thailand, the sheet metal products that were produced by rolling process have high demand and the consumption trend to grow in the future. Many new products, which made from rolling steel sheet, had been developed with various design. Thus the manufacturers have to improve the productivity through the investigation and analysis of different process parameters, which affect to the quality during the production. In this paper, finite volume method FVM had been applied to analyze different effects of processes parameters such as temperature, roller speed, friction, size and capacity of rolling machine. The commercial software MSC.SuperForge was used in the modeling and simulation of metal deformation under the flat rolling process. Considering the predicted results compared with the experimental data, the different in dimension error data were within an acceptable range of quality specification. The error in width of finished steel sheet was 1.17%, the length was error of 1.50%, and the thickness was error of 2.32%. By using this technique, different factors affected during rolling process can be investigated and controlled such as the metal flow, the distribution of stress and strain, and the deformation zone.

Abstract: First investigations focus on the usage, processing and material properties of polycarbonate (PC) based materials used in cable duct production. Test coupons were taken from in-situ cable ducts including further additives generally used in industry. Different mechanical and optical analytical methods were performed. Significant differences in tensile properties of polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) compared to mineral reinforced PC were observed. The hardness of mineral reinforced PC is significantly dependent on the geometry of the cable ducts. The fracture behavior and morphology of the PC/ABS fracture surface is directly related to the coupon temperature during Charpy impact testing. The process temperature influences the failure behavior during high impact processing such as high speed punching. Due to the lower impact strength of mineral reinforced PC less film and burr formation compared to PC/ABS are likely. However, the mineral distribution is not homogeneous and therefore subject to further investigation. This study aims at a better understanding of process properties of PC/ABS products, parameter selection, quality improvement and general understanding of underlying microstructural and surface properties.