Control of weld composition when arc welding high strength aluminium alloys using multiple filler wires

Abstract

An experimental method of controlling weld composition when welding Al2024 has been explored. Utilising the tandem process and a cold wire feed unit, two and three commercially available filler wires were mixed in a single weld pool to control composition. Thermodynamic modelling was used to provide optimum weld compositions for the eradication of solidification cracking. Validation showed that by controlling the principal elements, not only was cracking eliminated, the mechanical properties of the weld could be varied. In particular, a composition was identified, which offered adequate joint strength and ductility. Exceeding this composition resulted in a corresponding increase in weld hardness at the expense of joint ductility.

Keywords

TANDEM WELDING FILLER WIRE DEVELOPMENT HIGH STRENGTH ALUMINIUM ALLOYS

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References

Campbell

and Stotler

: ‘Friction stir welding of armour grade aluminium plate’, Weld. J., 1999, 78, (12), 45–48.

Mishra

and Ma

: ‘Friction stir welding and processing’. Mater. Sci. Eng. Rep., 2005, 50, (1–2), 1–78.

Rhodes

C. G.

, Mahoney

M. W.

and Bingel

W. H.

: ‘Effects of friction stir welding on microstructure of 7075 aluminium’, Scr. Mater., 1997, 36, (1), 69–75.

Ericsson

and Sandstrom

: ‘Influence of welding speed on fatigue of friction stir welding, and comparison with MIG and TIG’, Int. J. Fatigue, 25, (12), 1379–1387.

Kou

: ‘Welding metallurgy’, 2nd edn, 263–299; 2002, New York, John Wiley & Sons.

Nelson

T. W.

, Lippold

J. C.

, Lin

and Baeslack

W. A.

: ‘Evaluation of the circular patch test for assessing weld solidification cracking’, Weld. J., 1997, 76, (3), 110s–119s.

Steenbergen

J. E.

and Thornton

H. R.

: ‘Quantitative determination of the conditions for hot cracking during welding for aluminum alloys’, Weld. J., 1970, 49, (2), 61s–68s.

Huang

and Kou

: ‘Liquation mechanisms in multicomponent aluminium alloys during welding’, Weld. J., 2002, 81, (10), 211s–222s.

Kerr

H. W.

and Katoh

: ‘Investigation of heat-affected zone cracking of GMA welds of Al–Mg–Si alloys using the Varestraint test’, Weld. J., 1987, 66, (9), 251s–259s.

10.

Miyazaki

, Nishio

, Katoh

, Mukae

and Kerr

H. W.

: ‘Quantitative investigation of heat-affected zone cracking in aluminum alloy 6061’, Weld. J., 1990, 69, (9), 362s–371s

11.

Gittos

N. F.

and Scott

M. H.

: ‘Heat affected zone cracking of Al–Mg–Si alloys’, Weld. J., 1981, 60, (6), 95s–103s.

12.

Cao

and Kou

: ‘Predicting and reducing liquation-cracking susceptibility based on temperature vs. fraction solid’, Weld. J., 2006, 85, (1), 9s–18s.

13.

Huang

and Kou

: ‘Liquation cracking in full-penetration Al–Cu welds’, Weld. J., 2004, 83, (2), 50s–58s.

14.

Mathers

: ‘The welding of aluminium and its alloys’, 49; 2002, Boca Raton, FL, CRC Press.

15.

Norman

, Hyde

, Birley

and Pragnell

: ‘Examination of the effect of scandium on 2000 and 7000 series aluminium alloy castings for improvements in fusion welding’, Mater. Sci. Eng. A, 2003, A354, 235–245.

16.

Pickin

, Williams

, Prangnell

, Robson

and Lunt

: ‘Control of weld composition when welding high strength aluminium alloy using the tandem process’, Sci. Technol. Weld. Join., 2009, 14, (8), 734–739.

17.

Huang

and Kou

: ‘Partially melted zone aluminium welds: liquation mechanisms and directional solidification’, Weld. J., 2000, 79, (5), 113s–120s.