Study On Microflow Of Liquid Metal In Micro Casting Forming

With the development of science and technology, making smaller product isactive demand. It makes the micro-machine become increasingly the front scienceand technology. Manufacturing micro machine demand a great deal of 3Dcomplex metal micro-components, but the existing micro processing techniquescan not make above-mentioned micro components. Micro-casting can produce 3Dcomplex the metal micro components with low cost, large quantity, and highefficiency. Compared to the existing micro-processing technology, the microcastinghas very special advantages.In the process of micro-casting, the liquid metal fills and flows in thecavity of mold, which is chilled by mold and cumbered by the air anti- pressureand capillary force, and then the filling mold is very difficulty. Therefore, themicro flow of liquid becomes the most difficult, and it is important to makinghigh quality 3D complex micro-castings.Therefore, by means of the numerical simulation, the aim of this paper is todiscover the microflow mechanism and the gas pore formation dynamicsregulation, and research the micro dimensions scale effect, the metals melttemperature, molding temperature, filling pressure, and the effect of wallthickness of mold on the microflow.This paper applies Fluent software to simulate the filling flow in the microtube and the micro wheel gear. The regulations of speed field, pressure field,temperature field, surface tension, and gas anti-pressure are thorough researchedin the micro-flow. In addition, the formation mechanism and dynamics regulationof gas pore are researched thoroughly in the filling of micro wheel gear.The results show that the micro dimensions flow regulation is differentfrom the macro view dimensions liquid metals. In the micro-casting process, themicroflow of the liquid metal in the micro dimensions scale mold appears manythe micro scale mold effect, which is different from the tradition cast, such as themicro dimensions flow bottom of convex enter effect, attach a noodles layeropposite thickness gradient effect and negative pressure steps degree effect etc..The numerical simulation result is agreed with the experiment result. Itshows that the mathematics model is accurate credibility, and which can exact discover basic regulation and mechanism of microflow in the micro dimension,thus, which provides theories instruction for further excellent the filling of liquidmetals and micro-casting process.