Mechanical Engineering for Society and Industry

Effect of sandblasting on the characterization of 95MXC coating layer on 304 stainless steel prepared by the twin wire arc spray (TWAS) coating method

2024-11-07T06:15:08+00:00

Twin wire arc spraying (TWAS) is a thermal spray process that is widely used in various industries. Nevertheless, the impact of repeated sandblasting on the coating characteristics of FeCrBSiMn coating created using the TWAS technique has not been extensively researched. Therefore, this study aims to investigate the influence of repeated sandblasting on the properties of the FeCrBSiMn coating layer created using the TWAS process. The study used stainless steel 304, 75B, and FeCrBSiMn as the substrate, bond coat, and top coat materials. The substrate materials underwent sandblasting with a repetition of 1, 2, and 3 cycles before the coating procedure. The coating's quality in this study was assessed using surface roughness, thickness, hardness, corrosion rate, bond strength, and SEM (Scanning Electron Microscope) examination. The findings of this investigation indicate that the sandblasting treatment substantially elevates the surface roughness of 304 stainless steel substrates. As the substrate surface becomes rougher, there is an increase in the percentage of porosity and unmelted material, as well as an increase in the thickness of the coating layer. Furthermore, the hardness of the resulting coating layer diminishes. Specimen A exhibited superior qualities in comparison to the other specimens. The coating layer on this specimen has a percentage of unmelted material and porosity, thickness, hardness, and adhesion of 7.122%, 0.125 mm, 1081.6 HV, and 14.5 MPa respectively. This investigation's results indicate that the substrate material's corrosion rate (x 10−6 mmpy) is 3648.6, which is lower than the corrosion rate of specimen A, which is 37.802.

Evaluation of a diesel engine performance and emission using biogas in dual fuel mode

2024-11-07T06:21:50+00:00

Environmental pollution and the gradual depletion of fossil fuels have recently shifted the focus to alternate fuels. Hence, more diversified research on alternate fuels is necessary to deal with the global energy crisis. Biogas extracted from biomass is an excellent alternative to fossil fuels due to its low cost and good mixing ability. It is mainly generated by anaerobic digestion of organic waste products in a digester tank. The present paper investigates the performance and emission characteristics of diesel engine in dual fuel mode with biogas as main fuel and diesel as pilot fuel without any engine modification. The main aspect of the paper is to critically study the effect of supplementation of biogas on diesel engine efficiency and emission level of important constituent gases such as CO₂ and NO_X. Our findings demonstrate that the essential performance result of engine, such as Brake Thermal Efficiency (BTE) and Mechanical Efficiency for the biogas-air mixture of 20% (DB20), was slightly decreased. At the same time, there was a reduction in brake-specific fuel consumption (BSFC) compared to pure diesel. Furthermore, the exhaust emission of NO_Xand CO₂ was lowered when the engine was operated in dual fuel induction mode. The results of engine performance were found to be better than the results of other researchers for engines of same specifications and operating conditions. Hence, biogas serves as a viable alternative fuel and contributes to cleaner combustion, offering a promising solution for reducing the environmental impact of diesel engines. The study provides critical insights into optimizing dual fuel systems for enhanced performance and sustainability.

Mechanical behavior of glass fiber-epoxy composite laminates for ship hull structures

2024-11-07T06:28:22+00:00

Polymer composite is widely used in various structures due to its strength-to-load ratio. Despite the significant benefits, many structures are vulnerable to high-impact loads in practical situations. Therefore, this research aimed to explore the effect of fiber arrangement on the mechanical behavior of glass fiber-epoxy composite laminates. Experiments were conducted on several samples with glass fiber arrays of Chopped Strand Matt (CSM), Woven Rovings (WR), and Woven Cloth (WC). The composite fabrication was molded using the vacuum pressure infusion (VAPRI) method. The mechanical behavior of laminate composite was obtained using a tensile test, tree point bending, shore D hardness, Charrpy impact, fracture observation, and fiber-matrix delamination. The results showed that WR arrangement excelled in various mechanical behaviors, including flexural strength 6992.6 Mpa, Hardnes 75.66 HD, and Impact 0.1789 J/mm. In comparison, the highest tensile strength value was obtained in the WC arrangement of 73.24 Mpa. This research showed that both regular and arranged fiber provided better mechanical properties than random fiber. The incorporation of fiber arrangement could be recommended in the further development of high-performance polymer composite.

Exploring the feasibility of SS316L fabrication via CMT-based WAAM: A Comprehensive study on microstructural, mechanical and tribological properties

2024-11-07T06:57:22+00:00

Additive manufacturing (AM) is revolutionizing production, enabling the customization of components for specific applications while promoting sustainable and on-demand manufacturing. This innovative method is especially valuable for producing intricate and custom parts from metallic materials like SS316L. Known for its excellent corrosion resistance and high strength, AISI 316L austenitic steel is widely utilized in aerospace, medical, automotive, and marine industries. This study explores the deposition of multi layered SS316L wall using the Cold Metal Transfer (CMT)-based Wire Arc Additive Manufacturing (WAAM) technique. The resultant multilayered wall exhibited seamless fusion devoid of macroscopic defects. A comprehensive analysis of its morphology, microstructure, mechanical properties, and tribological performance was conducted. Microstructural examination revealed a progression from fine equiaxed grains with ferrites in the lower sections to coarser columnar grains with acicular ferrites in the upper sections. Vickers microhardness and Charpy impact tests indicated a decline in hardness and impact energy from lower to upper sections. Uniaxial tensile tests demonstrated decreasing yield and ultimate tensile strengths, alongside significant ductility and toughness. The coefficient of friction and wear rate escalated with higher loads and from lower to upper sections, predominantly displaying abrasive wear mechanisms. These results validate the efficacy and durability of the SS316L CMT-based WAAM process in fabricating high-quality structures with tailored mechanical and tribological properties.