5 research outputs found
Influence of oil-based and water-based lubrication on tool wear of DLC/TiAlN-coated punches in blanking of stainless steel
No full textThis study aims to eliminate the use of oil-based lubricants in the metal forming process by integrating a new tribological system of double-layered Carbon/Titanium Aluminum Nitride (DLC/TiAlN) with water-based lubrication. The research compared the performance of traditional oil-based lubricant (cutting fluids) against water-based lubricants containing Magnesium Oxide (MgO) and Silicon Carbide (SiC) nanoparticles. This waterbased lubricant, prepared through a two-step method, is applied to the surface of 1 mm thick SUS304 stainless steel during the blanking process. A mixture of MgO and SiC reduces the coefficient of friction more effectively than when using a single additive. The combined effect of using DLC/TiAlN-coated tools with water-based lubricants with MgO/SiC additives increases resistance to galling, leading to a 14% reduction in draining force compared to dry friction and a 3% reduction compared to cutting fluids. Moreover, the combination of MgO/SiC minimizes the formation of burrs at the edge of the product during the blanking process. The water-based lubricants with MgO/SiC are a competitive alternative to oil-based lubricants in the metal forming industry
Investigating fertilizer spreader blades for improved flow behaviours and material resilience in palm plantation settings
No full textFertilizer spreaders play a crucial role in evenly distributing granule fertilizer across palm plantations. However, in specific areas where growth conditions are unsuitable, fertilizer application becomes unnecessary. Therefore, this study aims to improve granule fertilizer distribution efficiency through enhanced fertilizer blade design. Using Finite Element (FE) simulation, the stress deformation and deflection of the existing spreader blade were evaluated. Meanwhile, Computational Fluid Dynamics (CFD) simulation was used to investigate the influence of spreader design on fertilizer projection speed and direction in the case of open and closed side discharge. The study revealed that the applied forces increased both the critical stress deformation and deflection. To ensure the fertilizer spreads properly over the desired area, the initial velocity had to be increased proportionally with an increase in the angle of direction. These findings contributed to a deeper understanding of the relationship between fertilizer projection velocity, spreader blade strength, and flow behaviour, enabling the reduction of waste in granule fertilizer, while enhancing the operational efficiency and reliability of fertilizer spreader
Enhancing wear resistance in blanking and punching of stainless-steel sheets under dry friction and solid lubrication conditions using single-layer ceramic- and carbon-based hard coatings
No full textPunching and blanking encounter challenges in separating tool and workpiece surfaces due to the formation of highly active virgin material, negatively impacting tool surfaces and product quality. To prevent this issue, hard coatings are applied to the tool surfaces. In this study, the wear severity of ceramic-based (TiN and TiAlN) and carbon-based (DLC) coatings deposited on punches during blanking and punching under dry friction and solid-form graphite lubrication were evaluated and compared with uncoated punches. The experiments were performed on 1-mm AISI304 stainless steel sheet thickness at room temperature. The findings indicate that there were no significant differences in force and wear measurements when using all test coatings in dry friction conditions. However, when applying a thin layer of TiN ceramic coating on the tool surface and using solid graphite lubrication, it effectively protected the tool and reduced punching force by 7. This combination also improved wear resistance in the shearing zone, resulting in an extended tool service life and enhanced surface finish
Enhancing physical, mechanical, tribological and contact characteristics of water-based lubrication using ceramic nanomaterials MgO and SiC for metal-to-metal sliding interfaces
No full textWater-based lubricants offer cost-effective benefits and are safer for both the environment and human personnel compared to oil-based lubricants. In this study, ceramic-based nanoparticles, namely MgO and SiC, were investigated as nanoadditives to enhance the performance of water-based lubrication. The methodology involved formulating the nanoparticles in water-based lubricants and characterizing the sedimentation, physical, mechanical, thermal, and tribological properties. The results demonstrated that the dispersion stability of the lubricants improved when mixed with Glycerol and Polyvinylpyrrolidone. The comparison between MgO and SiC nanoparticles in water-based lubrication revealed enhancements in viscosity, friction, wear, and thermal properties. This improvement was further validated through FESEM-EDS analysis, which revealed a reduction in friction and wear owing to the ball-bearing effect and the formation of a protective film. Moreover, the study highlighted the deposition of nanoparticles on the contact surfaces, which not only facilitated the mending effect but also played a significant role in reducing surface roughness by acting as a polishing agent
Surface and optical characteristics of polycrystalline GaN layer with different pores profile of porous GaAs/GaAs substrate
No full textThis work investigated the influence of pores profile of a porous GaAs/GaAs substrate on surface and optical characteristics of an over-deposited GaN layer. Different pores profile of the porous GaAs/GaAs substrate was introduced by varying the DMF concentration of 50%, 75% and 90%. The pores distribution is more uniform, while the pores size is bigger with higher DMF concentration. In contrast, the pores depth is less deep when the DMF concentration was higher than 75%. Next, the GaN layer was deposited onto the porous GaAs/GaAs substrate using an e-beam evaporator system, followed by thermal annealing in ammonia ambient. It was found that the porous GaAs/GaAs substrate, etched by the DMF concentration above 75% gave lower surface roughness to the polycrystalline GaN layer although the surface morphology showed no significant changes. XRD measurement showed on non-porous substrate favoured hexagonal growth in the polycrystalline GaN layer. Instead, the porous GaAs/GaAs substrate favoured the cubic growth, especially the porous GaAs/GaAs substrate etched by 75% DMF concentration. Moreover, the GaN layer on the porous GaAs/GaAs substrate etched by 75% DMF concentration showed the smallest FWHM of NBE peak emission, while exhibited a relaxation level closer to a reported stress-free bulk GaN, as compared to other samples. After all, the porous GaAs/GaAs substrate, etched by 75% DMF concentration has improved the surface and optical characteristics of the layer due to its better porosity. © 2019 IOP Publishing Ltd
