| Résumé | Over conventional joining methods, linear friction welding (LFW) exhibits a high weld quality and economical benefits for the aerospace industry. In particular, LFW enables the removal of the fir-tree in conventional blade to disk assembly, which results in weight reduction and improvement in engine efficiency. Considering these advantages, the LFW behavior of Waspaloy, used in jet engines as blade and disc material, has been investigated at different processing conditions. This study specifically highlights the influence of frequency, amplitude, and pressure during oscillation on the microstructure and mechanical properties of the welded samples. Microstructure and mechanical characteristics of the thermo-mechanically affected zones (TMAZ) were investigated by optical microscopy, EBSD, SEM, and microhardness. The LFW operating window resulting in welds free from defects was determined from these data. Microstructure examination revealed that dynamic recrystallization (DRX) occurred in the 0.9 mm narrow band of the TMAZ resulting in up to 50% reduction in the grain size. Furthermore, at the weld interface a considerable volume fraction of the ?' precipitates dissolved, contributing to a drop in hardness. |
|---|
