ORBITAL FRICTION WELDING OF TITANIUM BLISKS: PROCESS CHARACTERISTICS AND MICROSTRUCTURE DEVELOPMENT

摘要

Orbital friction welding is introduced as an alternative welding process for the manufacturing of Titanium blisks. In addition to the advanced process characteristics;; the influence of the relative motion on the microstructure development in the weld zone was investigated. EBSD measurements revealed a stronger texture in Ti-6Al-4V linear friction welds in the direction of the reciprocating motion as compared to orbital friction welds at the same position. By performing a parameter optimization for Ti-6Al-4V orbital friction welds it was found, that due to a gradually increase of the friction pressure it is possible to decrease the welding temperature. This process control enables to avoid the α-β-phase transformation which is known to cause high tensile residual stresses in the weld line of Ti-6Al-4V linear friction welds.