The use of NiAl Coating Deposited by ESD Against the Wear of Sliding Wire in GMAW Contact Tips

Abstract

The wear during the sliding of wire in GMA welds causes the contact tips to be replaced after a certain number of hours of service. In order to reduce the wear, GMAW weld contact tips were coated by NiAl using ESD (Electro Spark Deposition) with 60V and 500 Hz under Argon. The testing of contact tips were done on robotic GMAW stations and standard metallographic techniques and SEM microscopy were used to reveal the microstructure. The results indicate that the service life of contact tips can be extended as much as 50 % compared to uncoated contact tips in concern via the use of W and NiAl coating, affecting the wire friction wear performance during high temperature welding process