Infiltration of Cellular Silicon by Molten Magnesium Alloys

Abstract

Open-pore cellular Si structures are manufactured by investment casting and, subsequently, infiltrated with molten Mg(-Sn), representing the initial state for a formation of the intermetallic compound Mg 2 Si 1-x Sn x . The processing parameters which govern the evolution of microstructure after the infiltration process are studied in the alloy systems Mg-Si and Mg-Si-Sn. The resulting microstructures are analyzed using SEM and EDS. It is found that an initial diffusion layer is already formed after infiltration. Its thickness can slightly be increased by raising the infiltration temperature of the Mg(-Sn) melt. A variation in mold temperature does not show a noticeable impact. The comparison of the diffusion layer formed in the systems Mg-Si and Mg-Si-Sn showed that a lower Sn content resulted in thicker layers.

Investigation of a Template‐Based Process Chain for Investment Casting of Open‐Cell Metal Foams

“…Open‐cell aluminum foams were manufactured using a modified investment casting process, which is described in short. [ 27 ] The given polymeric templates, with outer dimensions of 40 × 40 × 20 mm 3 , were prepared for casting by adding a melt‐feeding system made from wax, which was attached to the planar side face of each polymer foam. These casting precursors were transferred into a stainless‐steel cuvette and embedded in a sulfate‐bonded ceramic investment (Prestige UNICAST, supplied by Certus—Investment Powder Technologies Co., Ltd., TUR).…”

“…additive manufacturing. [27,28] In the case of additively manufactured sacrificial structures, the problem of high-volume scalability remains. In terms of reticulated foams, PU or PE foams are commonly used.…”

“…[ 25,26 ] Given the need for an open‐cellular structure, sacrificial polymer templates for investment casting range from reticulated polymer foams to theoretically generated open‐cell structures, which are produced by additive manufacturing. [ 27,28 ] In the case of additively manufactured sacrificial structures, the problem of high‐volume scalability remains. In terms of reticulated foams, PU or PE foams are commonly used.…”

Mechanical and Degradation Behavior of Zinc‐Based Biodegradable Metal Foams

“…Open-cell zinc foams were fabricated with various densities and pore sizes. An investment casting method combined with a thermal-additive process [41] was used to achieve a variation of the relative density, by changing the reticulated polymer foams' strut thickness while having two different pore densities (13 and 15 pores per inch (PPI)). Table 1 shows the nomenclature and morphological parameters of the tested foams.…”

Diffusion‐Triggered Synthesis of Mg2Si Based on Infiltrated Silicon Structures in Molten Mg

“…An initial diffusion layer of the intermetallic compound Mg 2 Si is formed at their interface after infiltration. [ 16 ] In the final step, the samples are thermally treated, which initializes the diffusion process between the Mg matrix and Si structures. The aim of this study is to investigate the formation of the intermetallic compound Mg 2 Si after the liquid–solid reaction.…”