The gear manufacturing method is an important determinant of their performance and service life. Surface hardness and dimensional accuracy play a significant influence in determining wear and contact fatigue in gears. This study’s goal was to measure the gear profile dimensions and surface behavior of nodular cast iron made using the chill casting technique. Chill plates made of 304 stainless steel with thicknesses of 0.2, 0.4, and 0.6 mm were used to provide good surface cooling rates during the chill casting of gears performed using open molds of silica sand. Chill plates are plated onto the walls of the mold, and then the molten material is poured at 1400 °C. The obtained gears were tested using photographs, microstructures, SEM-EDX, microhardness, wear, and dimensional measurements. The thickness of the chill plate can affect the hardening process of the gear surface. Thicker chill plates result in slower cooling rates, resulting in a more homogeneous microstructure and increasing the hardness level of the hardened layer. Whereas thinner chill plates result in a faster cooling rate, which results in a higher hardness and wear resistance of the hardened layer. Reducing the thickness of the chill plate from 0.6 mm to 0.2 mm increases the cooling rate and increases the amount of diffusion that can occur. The results showed that M₇C₃ and the (FeCrC)₇C₃ matrices were formed, with an average hardness within a range of 700–994.96 HV. A chill plate with a thickness of 0.4 mm produces gear with the best accuracy and precision.

This study evaluates the performance of a copper-based metal matrix composite (Cu-MMC) brake pad fabricated by powder metallurgy for high-speed railway braking applications. The material was produced via homogeneous powder mixing, compaction at 650 MPa, and sintering at 950 °C for 2 h to promote densification and metallurgical bonding. The fabricated Cu-MMC exhibited densities of 5.71–5.98 g/cm³, porosities of 5.85–10.1%, and hardness values of 62–73 HV, indicating effective microstructural control. Tribological performance was assessed using a brake dynamometer at an equivalent speed of 160 km/h and a contact pressure of 0.95 MPa. The composite demonstrated a low specific wear rate of 0.11–0.14 cm³/MJ, meeting the TJ/CL 307-2014 standard for high-energy braking. Surface analysis revealed stable frictional behavior dominated by oxidative–abrasive, adhesive, and delamination wear mechanisms. Thermal evaluation showed a maximum operating temperature of 225–235 °C, below the softening temperature of copper, confirming adequate thermal stability.

Modulus of elasticity and Poisson's ratio are two material properties whose values are often used as input parameters in design, stress analysis and simulation of structures or machine element components. So far, the determination of both material properties uses modern methods which require quite expensive measuring instruments and measuring tools that have a high level of accuracy. In this study, the use of the on-off method in tensile testing to determine the elastic modulus of four types of metals is investigated. The four types of metal are AISI 1018 steel, AISI 1045 steel, stainless steel 304 and aluminum 1100. The results obtained show that the elastic modulus obtained is close to the reference elastic modulus value. Meanwhile, the Poisson's ratio resulting from this method is still not close to the Poisson's ratio from the reference. For this reason, measuring instruments that have higher accuracy are needed to get good results.