AC-GTAW of aluminium - new perspective for evaluation of role of positive polarity time

Experiments were carried out to determine the effect of the positive polarity time on cathodic cleaning, arc voltage, arc power and weld bead geometry on AC-GTAW of aluminium. Welding current was kept constant in both positive (EP) and negative polarity. During the experiments current and voltage mo...

Full description

Saved in:
Bibliographic Details
Published inScience and technology of welding and joining Vol. 15; no. 7; pp. 632 - 637
Main Authors Dutra, J. Carlos, Cirino, L. Machado, Gonçalves e Silva, R. Henrique
Format Journal Article
LanguageEnglish
Published London, England Taylor & Francis 01.10.2010
SAGE Publications
Subjects
AC-TIG
Aluminium
ALUMINIUM WELDING
Aluminum
Beads
CATHODIC CLEANING
Electric potential
Electrodes
FIELD EMISSION
Polarity
THERMIONIC EMISSION
VARIABLE POLARITY
Voltage
Welded joints
Welding
VARIABLE POLARITY
CATHODIC CLEANING
ALUMINIUM WELDING
THERMIONIC EMISSION
FIELD EMISSION
AC-TIG
Online AccessGet full text

Cover

More Information
Summary:Experiments were carried out to determine the effect of the positive polarity time on cathodic cleaning, arc voltage, arc power and weld bead geometry on AC-GTAW of aluminium. Welding current was kept constant in both positive (EP) and negative polarity. During the experiments current and voltage monitoring was performed to further analysis of arc voltage and arc power. There was an increase in the weld depth and fusion areas when longer EP times were used. This behaviour differs from the traditional literature relating to welding processes with non-consumable electrodes. However, this increase occurs from a certain point, when the EP time is >4·0 ms over a total period of 20·0 ms. The use of a minimum EP time was found to be sufficient to perform the oxide removal, yielding weld beads with satisfactory fusion characteristics and minimum wear of the tungsten electrode.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1362-1718
1743-2936
DOI:10.1179/136217110X12813393169570