Eutectic Composites.
Abstract
The effect of matrix and heat treatment on the creep resistance of gamma (Ni) - delta (Ni3Cb) and gamma, gamma prime' (Ni, Ni3Al) - delta (Ni3Cb) alloys was studied. These alloys consisted of three ternary gamma prime' - delta alloys (no chromiun) containing 2.8, 2.55, and 1.0 weight percent aluminum and two gamma-delta alloys, the binary eutectic Ni-Ni3Cb and a ternary Ni, Cr-Ni3Cb alloy. The alloys were produced with considerable care in order to have available for evaluation five different compositions with very similar matrix/reinforcement morphologies and an overall microstructural alignment as completely uniform as possible. Each gamma, gamma prime'-delta composition was tested as-solidified and in two heat-treated conditions (solution treated, air quenched and aged at 760 C for 24 hrs, or aged at 1000 C for 500 hrs). Electron microscopic examination of failed creep specimens indicated that formation of gamma or gamma and gamma prime' precipitates in the delta phase is a key factor in the high temperature creep deformation and fracture mechanism. Ultimately, the plate-like precipitates merged with adjacent plates to create zones in which the delta lamellae became separated by complete bridging of the gamma, gamma prime' type matrix phase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1975
- Accession Number
- ADA020331
Entities
People
- Edward M. Breinan
Organizations
- United Technologies Corporation