Mamdouh Ibrahim Elamy

ABSTRACT This study systematically investigated the influence of heat input and tool-pin geometry on the microstructural evolution and mechanical performance of friction stir welded AA5052/C12200 dissimilar lap joints. Welds were produced using three pin geometries (straight cylindrical, tapered cylindrical, and square-frustum) under rotational speeds of 750–1150 rpm and traverse speeds of 50–100 mm/min.

ABSTRACT This study explores the enhancement of Al–Si–Cu coatings via a post-deposition fast rotational rolling (FRR) process applied with one, two, and three passes. Friction surfacing initially refined the Si particles, reducing their average size to 5.1 ± 0.4 µm in the unrolled coating. Subsequent FRR passes further fragmented the Si particles, yielding mean sizes of 4.2 ± 0.3 µm, 3.7 ± 0.5 µm, and 2.5 ± 0.6 µm after the first, second, and third passes, respectively.

ABSTRACT This study investigates the advanced fabrication and systematic evaluation of copper–Al2O3 composites produced via deformation-driven metallurgy (DDM). Microstructural analysis revealed a pronounced gradient along the thickness: grain sizes decreased from 17.9 ± 0.8 µm at the bottom to 7.1 ± 0.7 µm at the top, while Al2O3 particle sizes simultaneously reduced from 8.2 ± 0.5 µm to 2.9 ± 0.6 µm.