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22MnB5 boron steel, an Ultra High Strength Steel (UHSS), is celebrated for its exceptional strength and wear resistance, making it highly valuable in automotive and other industries where lightweight materials are essential. Its superior wear resistance also makes it suitable for use in cutting tools. This study aimed to evaluate the performance of 22MnB5 boron steel as a turning insert for metal machining, specifically in relation to cutting speed and cutting environments. The 22MnB5 boron steel blanks were laser-cut into round shapes with a thickness of 2.6 mm and a diameter of 12 mm, following the RNGN 120300 standard. Machining tests were performed on AA 6061 aluminum alloy under both dry and wet conditions, with cutting speeds ranging from 100 to 450 m/min. The outcomes highlighted that 22MnB5 boron steel is effective for machining AA 6061, with tool wear stabilizing between 200 and 350 m/min. Tool wear ranged from 0.15 to 0.27 mm in dry conditions and was reduced to 0.08-0.18 mm in wet conditions. At lower speeds, built-up edges were the predominant wear mechanism, while at higher speeds, adhesive wear in the form of a tribolayer was more pronounced. These findings highlight the potential of 22MnB5 boron steel for efficient machining, particularly under wet conditions, offering valuable insights into improving tool life and reducing production costs. [ABSTRACT FROM AUTHOR]

The Instrumented Charpy impact test is a promising method for determining a material's impact response. Stainless steel has a higher impact energy absorption capacity, high tensile, and yield strength compared to aluminum. Performance varies among grades; for instance, Aluminum 7075-T6 exceeds Aluminum 6061-T6 in tensile and yield strength. However, information regarding their energy capacity and impact signal pattern is lacking. This study investigated the impact properties using a Charpy machine, a data acquisition system, and a sensing element. Strain gauges were used to record the impact strain signal, enabling the analysis of impact duration, maximum strain, and the area under the curve. Specimens experimented include Stainless Steel 304, Aluminum Alloy 6061-T6, and Aluminum Alloy 7075-T6. The Charpy machine measures absorbed energy, while the theoretical impact energy is computed from software data. The area under the strain-time curve reflects the material's energy absorption capacity. Stainless Steel 304 demonstrates superior energy absorbed, impact duration, and area under the curve, followed by Aluminum 6061-T6 and Aluminum 7075-T6. Despite higher tensile and yield strength, the inferior impact response of Aluminum 7075-T6 highlights the importance of factors like ductility, elongation, and alloy composition. Consequently, Aluminum 6061 is commonly used in the automotive industry, while Aluminum 7075 is preferred in aerospace applications. [ABSTRACT FROM AUTHOR]

The sintering temperature and holding time have a significant impact on the densification of a ceramic compact. In this study, alumina inserts were made with varying sintering temperatures and holding times. The procedure began with the compacting of alumina powders inside a mould with trapezium and round shapes. These inserts were then sintered between 1200 °C and 1400 °C for 5 to 9 h holding time. The sintered samples underwent analysis based on the shrinkage size, density, and microstructure. The sample with the highest density was chosen for additional machining tests. The results showed that the alumina shrinkage ranged from 3 to 6%, with a maximum relative density of 91.3% recorded when the sintering parameter was applied at 1400 °C and a 9 h holding time. The transition of the grain growth was observed depending on the sintering temperature and heating duration. When machined with AISI 1045 carbon steel, the sintered alumina inserts achieved a maximum tool life of 35 s at a cutting speed of 350 m/min. The sintered inserts exhibited brittle characteristics with a dominant notch wear and abrasive mechanisms. [ABSTRACT FROM AUTHOR]

Composite materials have gained wide acceptance among industries since the past decades. They have been widely employed in a wide variety of engineering applications. In this research, the influences of fibre stacking configurations on the indentation behaviour of pineapple leaf/glass fibres reinforced polypropylene hybrid composites were investigated. The indentation behaviours of hybrid composites were then compared to non-hybrid composites. Composites were fabricated through the hot press moulding compression technique using hydraulic hot press machine. The indentation behaviours of composites were presented in terms of maximum indentation force, energy absorption and specific energy absorption. The damage mechanism of composites was also studied after the indentation test. From the findings, it was concluded that the partial incorporation of glass fibre in the composite laminates improved the indentation resistance and energy absorption. In overall, nonhybrid glass fibre reinforced composite laminates showed the highest indentation resistance and energy absorption. However, the hybrid composites with the substitution of middle glass fibre with pineapple leaf fibre had a comparable indentation resistance and energy absorption to the non-hybrid glass fibre based composites. Therefore, these results have evidenced the potential of hybrid composites to supersede non-hybrid glass fibre based composites. [ABSTRACT FROM AUTHOR]

Fatigue damage assessment is essential in determining the durability of automobile components. Several studies have been conducted on fatigue durability of steering knuckle using constant amplitude loading. However, most of the engineering structural and components are subjected to Variable Amplitude Loadings (VALs) in service. Therefore, this study aims to present a fatigue damage simulation of automobile steering knuckle of a 1300 cc national automobile using finite element analysis. In this study, the steering knuckle is modeled using computer-aided design software, in which the dimensions are assigned according to 3D scanning files. The critical area on the steering knuckle is determined using commercial finite element software. The strain gauge is then mounted on the steering knuckle and connected to a data acquisition system to capture the actual fatigue strain signal while driving on a residential road. The fatigue strain signal is then used as the VAL in the fatigue damage simulation of automobile steering knuckle. Forged steel, cast aluminum, and cast iron are used and analyzed in the simulation. Results indicate that the different types of material used significantly influenced the fatigue damage of the automobile steering knuckle. [ABSTRACT FROM AUTHOR]