Fabrication Method for Porous Metals using Ultrasonic Microbubble Generator

抄録

A novel method to fabricate closed-cell porous metals from low melting point alloys is developed by blowing microbubbles into the molten metal using an ultrasonic bubble generator. As it does not require additional materials such as thickener or foaming agents, the developed method is simpler and more economical than conventional methods. The fabrication setup consists of a gas supply system, a temperature regulator, and a microbubble generator; the ultrasonic waves of the microbubble generator break the gas injected to the molten metal through the tip of a hollow horn down into microbubbles. Their low buoyancy causes the generated microbubbles to remain in the molten metal until they are solidified during cooling. Furthermore, the formation of foams during the process resulted in a closed-cell structure. The porosity of the closed-cell porous metal fabricated in this study was found to be greater than 70%. Moreover, the porous metal which can be fabricated has micropores. This technology makes it possible to fabricate porous metals more economically and simply than conventional methods, and if mass production is possible, it is an innovative method.