| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 829558 | Materials & Design (1980-2015) | 2014 | 7 Pages |
•Critical temperature is discovered for hot deformation of Nimonic 80A.•Critical temperature is illustrated by changes of lattice constant, secondary phases, etc.•Modified strength equation is proposed based on dynamic microstructure evolution.
The deformation behavior of Ni76Cr19AlTiCo has been investigated under compressive strains by up to 50% at temperatures ranging from 800 °C to 1150 °C, and at strain rates from 0.001 s−1 to 1 s−1. A dramatic change in the mechanical properties of the alloy was observed when the temperature was increased from 850 °C to 950 °C, along with a rapid increase in grain size with increasing the temperature. Recovery and recrystallization processes occurred under deformation at temperatures above 950 °C. The degree of recrystallization was found to increase with increasing temperature or decreasing strain rate. γ′-phase precipitation occurred in the matrix and the particle sizes and the number of the precipitated phases were found to increase with increasing temperature or decreasing strain rate. Grain boundary precipitation of chromium carbides has also been observed, but its influence was negligible because of the small amount of the precipitates present in the matrix.A modified Hall–Petch equation was proposed to predict the mechanical properties of the alloy based on grain growth and microstructure evolution.
Graphical abstractThe relations between ultimate strength of the nickel-based alloy and temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide
