Hill Engineering Blog

In a previous blog post we discussed, in general, issues related to residual stress in welding. In this post, we’ll follow up with a more detailed look at a specific welding application – linear friction welding of titanium alloys.

Titanium alloys are widely used in aerospace applications for their high strength to weight ratio, good corrosion resistance, and metallurgical stability. New joining methods are being implemented that allow for more efficient manufacture of titanium components. Linear friction welding (LFW) is a solid phase bonding process, which is particularly appropriate for titanium alloys. Due to the titanium’s great affinity for oxygen, nitrogen, and hydrogen, protective atmospheres must be used to prevent contamination of the welded material. LFW avoids the formation of a liquid phase during the welding process, and can therefore be carried out in air. Likewise, the typical defects caused by melting and solidification during traditional welding process such as pores, pinholes, shrinkage cracks and grain coarsening are avoided. However, as with all welding and deformation processes, understanding the weld residual stress is important. Continue reading Residual stress in linear frictions welds

Welding is a very common manufacturing process that is used to join materials together to form assemblies and systems. In many cases the welded joints are large, have reduced material properties (e.g., stress corrosion cracking resistance, fracture toughness), and contain defects. The welded joints tend to be critical locations in terms of design and sustainment. For this reason, residual stress in welding is a primary concern. Hill Engineering has extensive experience with residual stress measurements and welding residual stress. Continue reading Residual stress in welding