Search Results

The atomization of molten aluminum when injected during high-pressure die casting is analyzed to determine its effect in enhancing the strength of the product being cast. In the previously reported first step of this study, molten aluminum was injected into open space and its atomization was observed photographically. Now in the second step of the study, a simulation is conducted to determine how the molten aluminum becomes atomized at the injection nozzle (gate) and how this atomized material flows and fills the cavity. A new simulation method is developed based on large-eddy simulation coupled with the volume-of-fluid method. The simulation system is verified by comparing its output with photographs taken in the first step of the study. Simulations are then conducted using an approximation of a real cavity to visualize how it is filled by the atomized molten aluminum.

With the growing demand of weight reduction in recent years, hollow structural casting products, which are weldable, of high strength and rigidity, are produced by high-pressure die-casting. In order to develop such a cast product in a short period of time, techniques are required to predict the castability, weldability, strength, quality at an early stage of development. The conventional simulations, however, are unable to satisfy the aforementioned demands. In an attempt to respond to those demands, the authors through this reported research quantifiably analyzed the porosity in the casting, and realized predicting of actual strength and elongation. By applying the newly developed casting simulation to the motorcycle parts, the cast part design can be accurately verified, allowing signification reduction of the thickness and weight.

In motorcycles, the materials of frame have been switched from steel to aluminum for the purpose of reducing weight while improving the rigidity of chassis. It was made possible to use aluminum frames for a number of commodity categories, by the development of technology through new structural designs to make the most of the characteristics of aluminum, the advancement of computer simulation system and the progress in material and production engineering. As the result of adopting aluminum for the frame, much higher performance has been realized by achieving a 40% reduction in the developed frames consisting of extrusions and castings for sports-oriented motorcycles and by suppressing the increase in fuel consumption. For low-priced utility vehicles such as scooters, the manufacturing process has been simplified by the development of the die cast two-split module frame.