الفهرس 
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Abstract
Semisolid metal processing (SSMP) is a technology that involves the formation of metal alloys between solidus and liquids temperatures. For the procedure to operate successfully, the microstructure of the starting material must consist of non-dendritic globular morphology for the solid phase in liquid matrix. Thus the process of SSMP relies on the thixotropic behaviour of alloys with a spheroidal rather than a dendritic microstructure in semisolid state. Currently, this process is industrially successful, generating a variety of products with high quality parts in various industrial sectors. This technology promises some advantages over conventional metal forming technologies. Aluminium alloys are among the most prominent and wellknown materials used in the mechanical construction and automotive industries. This investigation is focusing on the study of the significance of the cooling slope (CS) casting process parameters, that are, pouring temperature, cooling length, and slope angle on the characteristics of AA7075 high strength wrought aluminium alloy microstructure. The cooling slope casting is the simplest and cheapest technique for producing feedstock materials with non-dendritic microstructure. The AA7075 wrought Al alloy has many good prosperities such as high strength, high hardness, and light mass. It is widely used in aerospace and automotive field. Statistical analysis of data is performed to explore the effect of the process parameters on the microstructure of the AA7075 wrought Al alloy. It was found that there is an optimum condition for the studying process parameters that provides the best morphology of the microstructure and the maximum degree of uniformity. The results were verified by empirical formulas that emphases the calculated results. The optimum values of pouring temperature, cooling length and tilt angle were found to be 650 °C, 350 mm and 45°, respectively. The pouring temperature has highest statistical significance on the results. The correlation coefficients of the developed regression models for the average grain size, average shape factor, and aspect ratio are 0.997, 0.960, and 0.983 respectively, which confirms the effectiveness of the developed models.