Research on Obtaining Open-Cell Foam by Molten Metal Infiltration

Abstract

AbstractPorous metallic materials are the subject of numerous recent studies due to their ability to combine good mechanical and physical properties with low weight. Metal foams are an innovative and challenging class of materials. Due to their unusual physical, mechanical, thermal, and acoustic properties, they have been granted much attention by materials researchers in the last few years and are finding several structural and functional applications in different engineering fields. This foam was produced by a process, which consists mainly in infiltrating molten metal bed of silica gel particles. Later to use hydrofluoric acid (HF) as solvent. In this paper is presented obtaining of metal foam with open-cell. Microstructural analyses on foamed specimens showed uniform microstructure of ligaments and a very regular and well reproducible open-cell morphology. Compositional analyses on foamed specimens showed uniform microstructure of ligaments and the absence of SiO2 interaction with the metal reproducible open-cell morphology. The use of SiO2 beads as space holder results in cellular metals with a very homogeneous arrangement of almost spherical cavities. Additionally, because of the high chemical stability of SiO2, reactions between space holder and molten metal tend to be minimal or inexistent. This methodology is based on cheap commercial consumables and a simple technology, focusing on intermediate-density low-cost foams with interesting cost/benefits ratio. Keywordsinfiltrating molten metal, silica gel particles, microstructure of ligaments, microstructural analyses, open-cell morphology