QAYYUM Muhammad Saqib

Motorbike shock absorbers of gravity die cast aluminum A356.0 alloy were being imported in the as-cast condition and later on processed at local foundries and workshops by sub-vendors; whereas, in many instances a nearly solid block was cast locally and machined to achieve the desired shape but because of the too much thin wall thickness involved and troublesome nature of cores required; this eventually lowered the metallic yield and the machining cost was uneconomical. Furthermore, bigger cores resulted in fast freezing without even completely filling the mold cavity. The current research paper deals with the computational methoding, die designing, modeling and simulation, optimization and finally casting of these components. Initially a single piece per mold was suggested but later on considering the economics of the project two pieces i.e. left and right were recommended to be cast from a single sprue in each die with a vertically parted permanent die mold. Throughout the process a significant number of iterations were made to achieve the final design which ensured a laminar flow of liquid aluminum below the critical velocity; a set of well posited risers were added to compensate for shrinkage and porosity, which ultimately appeared away from the casting resulting in sound castings of excellent metallic yield.