Influences of welding parameters on the quality and creep properties of friction stir welded polyethylene plates

This work aims to investigate the effects of main friction stir welding (FSW) parameters on the quality and creep properties of polyethylene plate joints. Welding variables for analysis were rotational speed, traverse speed, geometry and tilt angle of tool. Indentation creep tests were carried out on weld joints, using a constant load of 1 kg f for 0.5, 2, 5, 15, 30, 60, 90 and 120 min. Also, classical power law, Juhasz, Ashby-Sargent and Mulhearn-Tabor methods were applied for calculating stress exponent values, as a criterion for creep evaluation. The results showed that under special conditions creep resistance of welds are better than that of the base material. Meanwhile, it was found that Mulhearn-Tabor method is the most conservative estimation for assessing the indentation creep behavior of specimens.