FABRICATION OF SILICON CARBIDE REINFORCED ALUMINIUM FOAMS USING FRICTION STIR PROCESSING ROUTE

Abstract

Microcellular materials and specifically metallic foams have attracted the attention of scientific community due to the advanced combination of particular properties that they offer, compared to solid metals. These combined properties make them revolutionary materials for applications requiring more than one function such as high stiffness, fire protection and sound insulation. The present research focuses on the development of a method of producing composite metallic foam localized regions on metallic parts using a friction stir processing route (FSP). This route consists of friction stir processing passes for the integration of the foaming and the stabilizing/reinforcing agents in the aluminium matrix (precursor specimens) and a separate foaming stage at a laboratory furnace. More specifically, a mix of microsized particles of silicon carbide (stabilizing/reinforcing agent) and titanium hydride (foaming agent) were dispersed on bulk aluminium alloy AA5083–H111 using FSP. The integration of the mix was achieved via grooves which were constructed along the plate, parallel to the rolling direction. The parameters investigated during the experimental procedure were the groove geometry and the number of FSP passes. The analysed outcomes were the dispersion of carbide particles in the stir zone of the precursor and the porous structure and morphology of the composite foamed aluminium. The results were correlated with hardness evolution in both precursor and final foamed specimens.

Keywords

• friction stir processing
• porous materials
• aluminium foams
• composite metal matrix foams
• silicon carbide
• localized foamed structures