Efficacy of active cooling for controlling residual stresses in friction stir welds
Source: Science and Technology of Welding & Joining, Volume 15, Number 2, February 2010 , pp. 156-165(10)
Publisher: Maney Publishing
Abstract:This paper investigates the effect of active cooling on the development of welding stresses during friction stir welding by finite element modelling. The primary aim was to see if cooling powers, corresponding to those currently obtainable using liquid CO2 cooling systems applied in practically feasible locations could bring about a significant reduction in weld residual stress. Various cooling strategies were examined. The simulations revealed that a large reduction in residual stress can be obtained, particularly at the weld line, depending on the size, power and positioning of the cooling sinks. A heat sink placed as close as possible behind the heat source had the greatest effect on reducing the build up of tensile stresses. All the approaches tended to reduce the weld centreline stress more effectively than those at the heat affected zone/thermomechanically affected zone boundary (i.e. below the edge of the tool shoulder).
Document Type: Research Article
Affiliations: 1: School of Materials, Manchester University, Grosvenor St. Manchester M1 7HS, UK 2: Cranfield University, Welding Engineering Research Centre, Bedfordshire MK43 OAL, UK 3: BAE Systems, Optics and Laser Technology Department, Advanced Technology Centre, PO box 5, FPC 267, Bristol BS12 7QW, UK
Publication date: 2010-02-01