Measuring residual stresses in linear friction welded joints composed by dissimilar titanium

Abstract

The Ti–5Al–2Sn–2Zr–4Mo–4Cr (Ti17) titanium alloy is the main material used in manufacturing blades and disks of aero engines, and it is always jointed with different microstructures for the design constraints. In this work, the residual stresses of linear friction welding of β Ti17 and α + β Ti17 are measured by contour method and the X-ray diffraction method. The welding-induced tensions were found to be greater on the β side than that on the α + β side, and had an obvious reduction in the weld centre. After the post weld heat treatment (PWHT) of 630°C for 3 h, all tensions on the β side relax to a very limited value while some new PWHT-induced compressions are found on the α + β side.