Fabrication of localised aluminium foam by a novel polymeric blowing agent

Madhu, H C and Kailas, Satish V (2018) Fabrication of localised aluminium foam by a novel polymeric blowing agent. In: MATERIALS CHARACTERIZATION, 142 . pp. 340-351.

PDF Mat_Car_142_340_2018.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

Closed cell aluminium foams are highly pursued, due to their unique combination of properties. However, the current applicability of the aluminium foams is limited due to issues like high costs, density-gradient and brittleness of the cell walls, which are either related to use of metallic hydride as blowing agent or liquid-state processing. To address these issues, this study presents a first attempt to use polymer as a blowing agent to foam an aluminium alloy. A polymer is Poly (methyl hydro siloxane) was dispersed into an A12024 sheet of 6 mm by Friction Stir Processing, in a localised region. This processed sample was pyrolysed at temperatures between solidus and liquidus (500-640 degrees C) of the alloy and at various durations (5-60 min) to foam the localised precursor. The density of resulting foams was measured by the Archemidies method and the resulting pore structures were characterised by Scanning Electron Microscopy (SEM) and micro X-ray Computed Tomography (CT). The results show that by as pyrolysis temperature increases relative density reaches a minimum of 0.65 at 560 degrees C. Beyond 590 degrees C, relative density increased from the optimum due to escape of foaming gasses. With increasing pyrolysis temperature, the pore size increased from few microns to several hundred microns. Further, quasi static compression test was done on as processed, solutionized and aged foams. Due to increased strain hardening in aged samples energy absorbed during compression increased by 80% in the plateau region. Hence, polymeric a blowing agent can be used to synthesize heat-treatable foams with controllable absorption energy.

Item Type:	Journal Article
Publication:	MATERIALS CHARACTERIZATION
Publisher:	ELSEVIER SCIENCE INC, 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
Additional Information:	Copy right for this article belong to ELSEVIER SCIENCE INC, 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	21 Aug 2018 15:50
Last Modified:	21 Aug 2018 15:50
URI:	http://eprints.iisc.ac.in/id/eprint/60479

Actions (login required)

View Item