Weldability of high-density polyethylene using friction stir welding with a non-rotational shoulder tool

ABSTRACT

This work studies the weldability of high-density polyethylene (HDPE) using the process of friction stir welding (FSW), with two different tools (one conventional tool and another with a non-rotational shoulder, called non-conventional). The comparative evaluation was performed using combinations of the parameters of rotational speed (v_W) and feed rate (v_A), which were adjusted for each tool. Weldability was evaluated based on visual inspection of the presence of discontinuities via stereoscopy and confocal microscopy and hardness in welded joints. As a result, it was found that the use of the non-conventional tool resulted in welded joints without any discontinuities and with an excellent external appearance thanks to less heat being used. The hardness in the stir zone was lower than that of the base material, showing different behaviour on the forward and backward sides depending on the parameters of the process.

KEYWORDS:

• Friction Stir Welding (FSW)
• Polyethylene
• Discontinuities
• Weldability

Acknowledgments

The authors would like to thank Universidad Autónoma del Caribe for the financial support provided through the CONV-I-004-P012 project. They would also like to thank Dr Juan F. Santa from Instituto Tecnológico Metropolitano (ITM) and Professor Ricardo Mendoza from Universidad Autónoma del Caribe (UAC) for their immense and voluntary contribution.