Coupling analysis on controlling mechanisms for creep of Al-Fe-Ni alloy
(1. State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China;
2. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
3. Laboratoire de Génie Civil et Géo-Environnement, Université de Lille, F-59000 Lille, France;
4. Anhui Aluminium Matrix Composites Engineering Research Centre, Huaibei 235000, China)
2. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
3. Laboratoire de Génie Civil et Géo-Environnement, Université de Lille, F-59000 Lille, France;
4. Anhui Aluminium Matrix Composites Engineering Research Centre, Huaibei 235000, China)
Abstract: The dislocation creep of Al-Fe-Ni alloy at both 300 and 400 °C was described by a coupling modification on analyzing the creep constitutive equation after introducing both threshold stress and load transfer coefficient. The quantitative results and microstructure characterizations showed that the complex interaction between dislocation and eutectic phase was the origin of threshold stress, and the modulus difference between matrix and eutectic phase induced the load transfer effect. Furthermore, the temperature effects on the modulus of matrix and eutectic phase were different, leading to the decline of threshold stress and increase of load transfer coefficient at higher temperatures. This was further evidenced by the finite element modelling analysis. Finally, the controlling mechanisms during dislocation creep of eutectic alloys were discussed in an increasingly quantitative manner.
Key words: dislocation creep; aluminum alloy; eutectic phase; load transfer effect; threshold stress