The Paton Welding Journal, 2009, №04



2009 №04 (03)

2009 №04 (05)

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TPWJ, 2009, #4, 21-26 pages  
MICROSTRUCTURE AND HARDNESS OF Al-Cu ALLOY (A2218) WELDED JOINTS PRODUCED BY GTAW


Journal                    The Paton Welding Journal
Publisher                 International Association «Welding»
ISSN                       0957-798X (print)
Issue                       № 4, 2009 (April)
Pages                      21-26
 
 
Authors
R. ALAPATI and D.K. DWIVEDI
Indian Institute of Technology, Roorkee, India
 
 
Abstract
This paper describes the microstructure, phase analysis and microhardness of Al-Cu (A2218) alloy welded joints produced by pulse gas tungsten arc welding process in as welded and heat-treated condition. Welded joints were produced by two combinations of pulse parameters. Decrease in hardness was observed with postweld heat treatment of welded joints. Higher pulse frequency of 100 Hz showed finer grain structure of weld metal as compared with that at low pulse frequency 50 Hz. Heat treatment led to significant reduction in fraction of second phase constituents in HAZ and weld metal, and spheroidization of the eutectic silicon took place.
 
 
Keywords: aluminium 2218 alloy, pulse TIG welding, pulse frequency, microstructure, microhardness, postweld heat treatment (T6), HAZ softening
 
 
Received:                11.06.08
Published:               28.04.09
 
 
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