Aluminium alloys are one of the preferred materials especially for land and air transportation because of their high strength and lowdensity properties. Although production using casting method is economical yet it has some disadvantages. Shrinkage which is occurred due to the density difference between the solid and liquid metal is prevented by feeders which need to be calculated. Liquid metal should be transferred to the mould without any turbulence. As a result, sprues are needed to be designed precisely. On the other hand, aluminium alloys can also be shaped by forging at semi-solid temperatures. There are some advantages compared to the traditional forging methods of improving die life due to the lower tonnage values. In this study, semi-solid produced 7075 aluminium alloy die filling capabilities were investigated. To achieve semisolid structure strain induced melt activated method (SIMA) was used. The desired structure was achieved at 635 °C and 30 minutes of duration of heat treatment. After determining the optimum parameters, metallographic analysis, density calculations, porosity distribution and tensile tests were carried out. It was found that the reproducibility of SIMA produced 7075 alloy was quite low. A proper tensile test result was achieved only 7 of the total 15 tests and the mean value was 386 MPa. The main reason for this scattered in mechanical properties could be the chemical composition of the alloy and the rapid solidification of the liquid eutectic phases. It is important to define the best fitting process parameters and controlling them precisely will be the most important factors for future studies.

Day-to-day life advanced composite materials usage is increasing continuously and replacing the existing monolithic materials. These composite materials are designed and fabricated for human needs with specific applications and also meet the standard requirements. In present study, the agro and industrial wastes derived ceramic reinforcements based Aluminium metal matrix composites, i.e. AA7075/welding slag and AA7075/Rice husk ash are fabricated through liquid metal stir casting route with varying the reinforcement contents from 2 to 12 (wt.%) in the matrix. Mechanical and microstructural characterization of the AA 7075 metal matrix composite were measured and compared to the base material. The results show an improved mechanical strength and high hardness in composites. Impact energy has also significantly improved at higher concentrations of reinforcement particles. Impact energy of the composites increases to 3 J for 9% and 12%, the maximum tensile strength obtained is 173 MPa for 12% Weld Slag MMC. The highest hardness achieved is 98 BHN for 12% Weld Slag MMC. Furthermore, the microstructural results reflect significant grain refinement with stir casting process with good interface characteristics in the matrix and uniform dispersion of agro reinforcement’s particles.

Severe Plastic Deformation (SPD) techniques have been used by researchers for last three decades in order to obtain Ultra-Fine Grained (UFG) materials. Equal Channel Angular Pressing (ECAP) is preferred more than other SPD techniques thanks to its high performance and practicability. Hexa Equal Channel Angular Pressing (Hexa-ECAP) – modified ECAP technique which enables to apply ECAP routes for cylindrical samples properly – was preferred in this study. Within the objective of this study, the effects of coefficient and ram velocity on the mean effective strain and strain inhomogeneity of Hexa-ECAP processed Al7075 aluminium alloy were investigated. Also, the effects of ram velocity and friction coefficient on hardness homogeneity were investigated benefitting from the similarity between the hardness distribution and the strain distribution.