A replication-casting device for manufacturing open-cell Mg foams

Abstract

The development of a replication casting device with the capability of manufacturing open-cell pure Mg and Mg alloys foams, with melting points lower than 950°C is described. The device consists of three basic parts: a cylindrical reaction chamber, a valve system for controlling the vacuum and the gas injection, and a heating system. The purpose of the present design was to improve the existing laboratory-scale devices, making them simpler than those reported in the literature, as well as to optimize the parameters (atmosphere, temperature, injection pressure, etc.) of the replication casting process. The proposed device has shown significant improvement over other devices reported, especially in terms of easiness of operation, adjustability and low cost of maintenance. The design of the device provides the ability to produce large foams free from defects such as large volumetric shrinkage and large concavities. The latter is minimized by the implementation of a perforated nozzle for gas impulsion. Examples of manufactured open-cell pure Mg and Mg–10wt.% Al alloy foams are also presented. The design is shown in a conceptual format; however it could be modified to produce larger or smaller samples.