Welding of Titanium and Titanium Alloys
Titanium and titanium alloys have excellent corrosion resistance, specific strength and ductility, good heat resistance, and low density that can match most applications. In addition, the relative cost savings for some titanium components can be significant. Because of these beneficial material characteristics and cost savings, the use of titanium and titanium alloys in the metalworking industry has grown significantly in recent years.
Before beginning to weld titanium and titanium alloys, it is important to understand the properties of the material and the special techniques required to properly weld it. Proper welding techniques and procedures will ensure that welds are strong, reliable and free of flaws.
Titanium and its alloys are highly reactive metals, having a greater affinity for oxygen than other metals. Therefore, it is important to ensure that the welding environment is free of oxygen and other elements that may react with the metal and cause contamination or defects. This is especially important when welding larger components and parts, as there is typically more exposure to the atmosphere.
Titanium and titanium alloys can be welded in both the GMAW (Gas Metal Arc Welding) and GTAW (Gas Tungsten Arc Welding) processes. These welding processes are relatively straightforward and can be done by most welders. For GMAW, a shielding gas such as helium or argon must be used. It is also important to select the correct weld filler metal that is suitable for the given grade of titanium or titanium alloy being welded.
GTAW welding provides a higher degree of control and precision and is usually the preferred method when welding titanium and titanium alloys. To ensure success, several key factors should be considered, including wire diameter, feed rate, travel speed, and heat input. It is also important to use a clean and non contaminated shielding gas. The use of a back purge will assist in creating a high integrity weld.
The welding of titanium and titanium alloys requires the proper selection of weld filler metal, and the understanding of proper welding procedures. When welding, it is important to be aware of the reactive nature of titanium and take steps to reduce exposure to oxygen and other contaminants. Following these guidelines will help ensure a successful and reliable welded joint.
