FRACTURE CHARACTERISTICS ANALYSIS RELATED TO THE MICROSTRUCTURES IN TITANIUM-ALLOYS

The micromechanism of fracture in coarse Widmanstatten alpha structure of (alpha + beta) type titanium alloys is discussed based on the frac ture mechanics related to the microstructural factors. The strengtheni ng mechanism in beta type titanium alloy is also discussed. The effect of microstructural refinement owing to the thermochemical processing using hydrogen, TCP, in the fracture characteristics, and the fracture characteristics of titanium alloys with the retained metastable beta phase are then described. Finally, the fracture characteristics of tit anium based intermetallics are related to the microstructure, where th e similarity of fracture characteristics in titanium based intermetall ics to that in (alpha + beta) type titanium alloys is introduced.