Materials Science Forum Vol. 1058

Abstract: GH3536 superalloy powder was prepared by the plasma spheroidization. The powder characteristics and effects of the plasma power on the percento spheroidization were studied.The phase and morphological properties of the powder were characterized by scanning electron microscope (SEM),Malven M4 particle size and shape analyzer and Leco ON736 oxygen-nitrogen analyzer.The results show that GH3536 fine spherical powder has favorable dispersity, smooth surface and high spheroidizing rate of 99%.The particle size distribution of the powder is narrowed,and the apparent density and tap density are significantly increased,which can meet the requirements of addictive manufacturing.

Abstract: A metallic part corrodes when it undergoes electrochemical reactions which cause the surface and structural deterioration of the metal. Through electroplating, metallic components can be protected from corrosion by coating them with Zn-Ni alloys. This study examined the electrodeposition of a Zn-Ni alloy film on a steel substrate from a chloride bath containing ethylene-diamine-tetraacetic acid (EDTA). A Pourbaix diagram using the OLI software was used to determine the stability of the Zn-Ni plating bath and the suppression of hydrogen evolution reaction (HER). Comparing the composition of Zn-Ni coating deposited in the EDTA bath with the pure Zn-Ni coating, the EDTA bath yielded higher deposition thickness and an average crystallite size reduction. The Zn-Ni coating deposited from the EDTA bath has a lower dissolution rate and better corrosion resistance properties than the non-EDTA bath. Polarization tests exhibited that the Zn-Ni alloy deposited from 0.119 mol/l EDTA bath at 20 mA/cm² current density showed lower corrosion current (Icorr) and more positive corrosion potential (Ecorr). Atomic force microscopy (AFM) and Vickers microhardness testing were used to characterize the morphological properties, topographic structures, and microhardness of Zn-Ni coatings.

Abstract: Rotary friction welding (RFW) result is much affected by heating and joining stage parameters. Heating stage is the period where friction takes place to generate heat at the interface. Parameters that alter the heating are friction pressure, friction time and rotation speed. In this work, experiment of RFW AISI 1045 and AISI 304 under different friction pressure and friction time was carried out. The objective was to investigate the relation between those parameters with the welding strength. The experiments were performed using one-factor-at-a-time (OFAT) strategy. A polynomial model of relation between joint strength with friction pressure and friction time was developed. Welding efficiency of 81.7% from the AISI 304 base metal was attained. Optimum setting friction pressure of under constant friction time was 40 bar, whereas the optimum setting friction time under constant friction pressure was 5 seconds.

Abstract: This research aimed to reduce die and punch wear and improved the quality of the production process with the application of the Lean Six Sigma methodology. Die and punch had limited capability in cutting material edges in the case study company. The root-cause analysis showed a correlation between the hard coating and the lubricant effect on wear reduction using the design of experiments and DMAIC based on the Six Sigma approach. The results indicated that a combination of AICrN-PVD coating and aloe vera oil provided the most outstanding results in terms of wear reduction. Moreover, it had the potential to minimize the cost of product defects or repairs significantly. These findings showed the effect of the Lean Six-Sigma approach at the die production process, which increased operational efficiency and consistency to enhance business performance and meet customer requirements.

Abstract: Standard test specimens are usually used to determine the tensile strengths of plastics. Their shape assumes that the material is homogeneous and only normal stress occur inside their nominal length. Unlike injection molding, which is a common technology to produce plastic parts, the structure of additively manufactured parts is not homogeneous. In areas with variable geometry, an additional internal stress concentration occurs, which often leads to failure of the test specimens outside their nominal length, which in turn compromises the tensile test. The stress concentration increases with the nozzle diameter used. This requires improvement of the test specimens shape. In the present work a new form of the test specimens is proposed, in accordance with the peculiarities of the Fused Deposition Modeling (FDM) process. A series of test specimens have been produced, using a 1mm and 2mm nozzle as well as one wall, no walls and milled specimens with newly developed geometry. All specimens were tensile tested and the results were shown and compared. It has been found that the proposed new shape ensures failure within the parallel length for successful testing, provided infill strands are correctly positioned.

Abstract: This paper mainly studies the position of the contact surface of the first ring groove of the piston under the condition of thermal mechanical coupling under the service conditions of the piston component of high-power diesel engine at the temperature of 350°C-420°C and the detonation pressure of the piston top of 28Mpa. For typical NDT defects such as surface crac0k, internal crack, shrinkage cavity and cold lap, the sensitivity of scale, morphology and position and their quantitative relationship. The crack defect on the upper joint surface of the piston ring causes the maximum stress in the range of 56.8 MPa-81.3 MPa. Among them, 8% of the circumference of a single defect will cause material damage and failure. Defects larger than this scale must be detected in eddy current NDT.

Abstract: In this study, an edible chitosan/castanopsis powder/essential oil ternary composite film was prepared by the casting film forming method. Prepare 1.5% chitosan (CTS) solution and 3% Castanopsis sclerophylla powder (ST) gelatinization solution respectively, and measure the CTS solution and ST gelatinization solution according to different mass ratios of chitosan and Castanopsis sclerophylla powder. Mix the liquid uniformly, add 15% glycerin to plasticize, then add different content of essential oil (EO) and Tween 80, high-speed shear mixing, vacuum defoaming, quantitative casting in the mold, drying at 45 °C to form a film .Through the study of the physicochemical properties and antibacterial ability of the composite film, the results show that the addition of an appropriate amount of Castanopsis sclerophylla powder can improve the physical and chemical properties of the composite film, and the essential oil can effectively improve the water barrier and antibacterial properties of the film. The edible film is used for fresh-keeping packaging of fresh meat, and the result shows that the edible film has good antibacterial and antioxidant effects.

Abstract: Vehicle lightweight promises to drive down the maintenance quality and increase energy efficiency in transportation with the safe and strength performance. The use of fiber reinforced polymer composite materials structural battery vehicles is recognized as an essential enabling technology for achieving high bearing capacity and energy storage capacity. At the same time it improves the energy storage capacity, the overall structural energy storage and space utilization of new energy vehicles. In this study we bring an idea to fabricate composites with integrated lithium-ion pouch batteries. The whole preparation process was carried out at room temperature to prevent thermal damage on battery. Experimental results indicate that the cyclic working voltage and capacity of CFRP structure battery are basically consistent with the monomer lithium-ion polymer battery which obtained from Xinwei battery testing equipment. Therefore, the fabrication process does not damage the lithium-ion polymer battery.

Abstract: A UV curable coating modified by several inorganic particles was prepared and characterized. Several kinds of inorganic particles including glass powder, mica, alumina, talcum powder and polyimide were introduced to epoxy acrylate (EA) as fillers and mixed with reactive diluent, photoinitiators, and other additives to obtain an organic-inorganic ultraviolet (UV) curable coating. Different kinds of inorganic powders were mixed in proportion to the formula and ground in a ball mill for 16 h to obtain smaller particles. The particle size and morphology of inorganic powders were characterized by laser particle size analyzer and scanning electron microscopy (SEM). The results indicated that the particle size of inorganic powders was reduced effectively after ball-milled. The morphology of the synthesized UV curable organic-inorganic composite coating was observed, and the mechanical and thermal properties of the coating were tested. Pure organic EA coating without the addition of inorganic particles was also characterized as controls. The distribution of inorganic particles in the coating was homogeneous and the surface of the cured coating was smooth. The results of mechanical properties tests showed that the addition of inorganic particles improved the hardness of the coating, but the effect on adhesion and flexibility was not significant. And the TGA curves showed that the thermal stability of the coating modified by inorganic particles was significantly improved compared with the pure organic coating.