Abstract
The lower ambient temperature fatigue life and higher fatigue data scatter of Ti-6 wt % Al-4 wt % V castings relative to wrought material, were investigated by analysing the nature of the crack initiation sites. Initiation mechanisms were characterized by precision sectioning the fracture surfaces at the crack nucleation locations. The combined effect of internal casting defects and a microstructure containing large colonies of similarly orientated α-platelets was found to be responsible for the low smooth fatigue life. The large scatter in the fatigue data was attributed to the variety of casting defects in the material and their large size distribution. Most failures that were examined initiated from defects close to the specimen surface possibly due to some bending moment in the axial cyclic loading. The free dendrite arms in the large shrinkage pores were shown to contain α-platelets in a colony arrangement. The shortest fatigue life associated with this type of defect was attributed to the notch effect of the dendrite arm interstices.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
