This paper presents a method for the determination of bending stress minimization of involute spur gears. A computer program has been developed to investigate the variation of bending stress and contact ratio depending on the pressure angle on the drive side. Since asymmetric tooth is not standard, the tooth model, which was introduced by DIN 3990/Method C and ISO/TC 60, has been adjusted for asymmetric tooth by the authors. The determination of the tooth form and stress concentration factors for asymmetric tooth has been accomplished for each different parameter (pressure angles, tool radius, rack shift, etc.). The sample results, which were obtained by using a developed computer program, are illustrated with numerical examples.

Basalt particles have been investigated as a novel additive for the production of glass fibre reinforced composite using sheet moulding compound (SMC) method. Compared to the CaCO₃that are widely used as filler in the SMC composite, the resulting composites exhibit improved mechanical properties. The tensile strength increased by approximately 15%, whereas the flexural strength was enhanced by 8% in SMC composites prepared by basalt particles. Examination of the surface morphology and interfacial debonding of the specimens is also performed via scanning electron microscopy. Superior strength properties are observed in the basalt particle-reinforced composites compared to those with the CaCO₃fillers.

Atmospheric pressure plasma (APP) applications have started to come to the fore today because of their fast and stable applicability to material surfaces and many advantages compared to plasma applications made under vacuum. With APP, it is possible to improve the surface energies, adhesion behavior and surface mechanical properties of materials. However, the changes obtained are not permanent since the surface tends to return to its untreated original state after plasma treatment. In this study, the wettability of APP treated metal surfaces, aging behavior and storage conditions that can delay the return of the surface to its untreated initial state were investigated. While one type of material (H300LAD), two different plasma treatments (cold and hot) and three different plasma treatment numbers (1, 2 and 3 times) were determined as test parameters; two different ambient conditions such as air and water (for 1, 10 and 60 min) were chosen as the storage conditions that can delay the return of the plasma treated surfaces to their original state. In addition, the effects of temperature on the aging time were investigated for two different temperature values (−20 °C and 30 °C). The effects of the applied plasma type, plasma treatment number, the storage conditions in which the samples were kept and the temperature on the aging behavior were evaluated and the conditions that could delay the aging time were investigated. The results showed that aging is greatly affected by the type of plasma applied to the surfaces, the storage conditions in which the samples were kept and the temperature.