Abstract

Dislocation mechanisms and their influence on mechanical properties (e.g. flow stress and work-hardening) can be studied in detail by critical prestraining experiments. In this study, the influence of prestrain on the flow stress of an Ni 3(Al, Ti) alloy with L1 2 long-range order structure was investigated. The yield strength has a positive temperature dependence (it increases with increasing temperature) from room temperature (RT) up to 450 °C. Prestraining of Ni 3(Al, Ti) single crystals at 800 °C activated the primary ± a[1 10](001) cube slip system. Climb dissociated segments interconnect superlattice dislocations of Lomer-Cottrell (LC) type. A subsequent additional deformation at RT introduced superlattice dislocations of the primary ± a[10 1](111) glide system. This subsequent deformation results in almost the same flow stress as the flow stress found in single crystals subjected to RT deformation only. Prestraining was found to have a huge influence on work-hardening. This is consistent with dislocation interactions of cube and octahedral glide systems. It is concluded that yielding is an intrinsic property of dislocation motion due to extended core configurations.

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 call

Disclaimer: 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.