| 초록 |
Metal foams are novel materials of physical, mechanical, thermal, electrical, and acoustic properties. Especially the open-cell Mg alloy material has a complex porous morphology consisting of an interconnected network, it is valuable to be a body-bone as a degradable biomaterial and a heat exchange material. The different pore size and relative density determine by the macrostructure and the mechanical properties. The open-cell Mg alloy foam was fabricated by investment casting method with enviromental protecting materials. The preparation technique for Mg based porous material with controllable pore size and uniform structure was obtained. The filler granular need resistance 700 ºC, and resistance to pressure. The granular make by plaster and perlite powder were adequately mixed as ratio of 1:1. An aqueous solution containing polyvinyl alcohol (PVA) was binder with the proportion of 4%. The results show that the key factors for the preparation of Mg based porous materials by gravity infiltration are casting temperature, negative pressure and preheating temperature of filler particles, and the filler particle size has influence on the preparation process. At the optimum casting temperature, preheating temperature of filler particles and negative pressure of 680−750℃, 400−500℃ and 300−1200 Pa, the best Mg alloy based porous material has the good fluidity and castability with the longest infiltration length, less defects and uniform pore structure. At that time, it gets 60%-80% porosity open cell Mg alloy foam. |
