Review on Fabrication of Gasar Porous Alloys

Abstract:

Gasar, which is based on the gap of gas solubility between liquid and solid metals, is a revolutionary process for fabricating porous metal. Recently, the research on fabricating porous alloys with ordered pore structure, has been one of the most popular topics and technical issues concerning the application of Gasar porous metals. The main reasons for difficulties in controlling the ordered porous structure include the influence of the “mushy zone” at the front of the interface during the solidification of the alloy, and the fact that after alloying elements are added, the solid-liquid interface becomes unstable and the solidification mode changes. Preliminary researches mainly focused on reducing the influence of the above two factors on the directional growth of pores from the following two perspectives: preparation technology improvement and alloy composition design (micro-alloying). This study reviewed the research progress of Gasar porous alloys based on the development of preparation techniques (mould casting technique→continuous zone melting technique→continuous casting technique), summarized the main factors that affect pore structure of porous alloys, and analyzed the shortcomings and development trends of future research.

Key words:Gasar;porous alloys;pore structure;solidification mode;mushy zone