The influence of friction time and contact angles in friction welding for Polyethylene pipes

Abstract

This paper is aimed to apply friction welding technique to weld HDPE pipes as well as to investigate theinfluence of friction time and contact angle to the property of joint. The welding machine was designed andmanufactured in order to conduct the experiment under various welding conditions. HDPE tubes were used inthis study and their outer diameter is 90 mm and 8.2 mm thick. The friction times were varied from 2, 3, 4, 5, 6,8 and 10 sec. While the contact angles were 0, 45 and 90. Other welding conditions were constant i.e.friction pressure (P1) 1 MPa, upset pressure 1 MPa, rotational speed 700 rpm and upset time 30 sec.The welded specimens were tested under tension, bending and pressure. The result suggested that asthe friction time increases, tensile strength, bending strength as well as pressure resistance of tube areincreasing. It was also observed that with the contact angle of 45 and 6 sec of friction time, the weldedspecimen has strength of 20.53 MPa which is about 15.86% higher than the master tube. In case of bendingtest, the tube with 45 contact angle provided highest value of bending resistance. However, it was observedthat as the value of friction time increases, the resistance of bending tends to increase in similar pattern forevery contact angles.