Effect of the weld thermal cycles of the modified indirect electric arc on the mechanical properties of the AA6061-T6 alloy

Abstract

Results of temperature measurements during welding of 12.7 mm thick AA6061-T6 alloy plates by modified indirect electric arc (MIEA) are presented. This study describes the thermal cycles in the heat-affected zone (HAZ) and also in the fusion zone. Depending upon the position of the transducers, the maximum temperatures measured in the HAZ ranged from 308 to 693°C, these measurements were related with the tensile test results and the failure zone reported previously by the authors (Ambriz et al., S&I 2006;11:10–17). It was observed that there is a decrease in the mechanical strength of the welded joints, due to the microstructural changes undergone by the AA6061-T6 alloy in which formation of the β′ occurs according to the time–temperature transformation diagram. The inherent cooling conditions of the weld pool observed for the MIEA technique (single welding pass) have made it possible to establish the characteristics of solidification and microstructure for a specific cooling rate.

Keywords:

• aluminium alloy
• melted pool
• heat-affected zone
• transformations
• overageing
• weld thermal cycle

Acknowledgements

The authors would like to thank the National Council for Science and Technology for its support, the Universidad Michoacana de San Nicolás de Hidalgo and, in particular, the Technological Institute of Morelia for all the facilities loaned for the use of its laboratories.

Notes

^1. [email protected]

^2. [email protected]

^3. [email protected]

Additional information

Notes on contributors

Ricardo R. Ambriz

1. 1. [email protected]

Gerardo Barrera

2. 2. [email protected]

Rafael García

3. 3. [email protected]