Beder, Murat; Varol, Temel; Akçay, Serhatcan Berk; Çuvalcı, Hamdullah; Erdemir, Fatih; Khan, M Adam; Yıldız, Uğur Temel

Reinforcing materials used in the production of metal matrix composites are used to improve the properties of the final composite. However, the compatibility between matrix and reinforcement and the reinforcement ratio directly affects the properties of the composite material. For this reason, low reinforcement ratios are preferred in many studies on ceramic particle reinforced composites. Unlike conventional studies, in this study, the effects of 10 wt%, 20 wt% and 40 wt% SiC content on the microstructure, dry wear properties and corrosion properties of Al2024 matrix composites were investigated. θ phase content became higher as the SiC content was increased. Hardness values increased with increasing SiC reinforcement. The highest value (307.68 HB) was obtained for the composite with 40 wt% SiC reinforcement, an increase of more than 100%. A decrease in volume loss with increasing SiC reinforcement was observed in the friction and wear tests. For 5 N of load and 1200 m of sliding distance, it was found that an addition of 40 wt% of SiC particles in Al2024 matrix results decrease in volume loss by almost 722%.

Topal, Umut; Uzman, Ümit

A procedure to select the optimum fiber orientations and determine the maximum load-bearing capacity of the simply supported symmetrically laminated plates combined the bidirectional tension loads and bending moments is described. The fiber orientation is considered a design variable. The optimization problem consists of two stages. The objective of the first stage is to maximize the strength of the laminated plates by determining the fiber orientations optimally while the objective of the second stage is to maximize each of the bidirectional tension loads and bending moments subject to the Tsai-Wu failure criterion for the optimum fiber orientations obtained from the first stage. The modified feasible direction method (MFD) is used as an optimization procedure. Therefore, a FORTRAN program is used for the finite element analysis and optimization routine. Also, the optimum fiber orientations are obtained using the golden section (GS) method to compare the results. Finally, the effect of the different plate aspect ratio, width-to thickness ratio, the uncertainties in the material properties and the uncertainties in the fiber orientations on the optimum results is investigated and the results are compared.