Magnesium2.6
High Temperature Performance of Al and Mg Based Alloys for Aerospace Applications
W. Kasprzak1*, D.L. Chen2, F. Czerwinski1, M. Niewczas3, G. Marzano4
1 CanmetMATERIALS
2 Ryerson University
3 McMaster University
4 Magellan Aerospace
High integrity cast components such as accessory gear boxes used in jet-engine applications, require higher service temperatures during continuous and peak operating conditions that could exceed 170 and 250oC respectively. This generates demands for developing new high performance materials with Al and/or Mg-based alloys being the primary candidates in these applications.
This study was aimed to evaluate hardness and transformation kinetics during aging between 25 and 500oC in Al-based (A356, F357, C355) and Mg-based (QE22A, EV31A, ZE41A, WE43B) alloys and to determine the maximum temperature the alloys can withstand without drastic loss of hardness.
Results revealed that A356 and F357 alloys showed softening at 225oC associated with hardness drop from 95 to 30 HRB. C355 alloy exhibited improved hardness retention since softening was observed above 240oC resulting in hardness decrease from 95 to 45 HRB. Temperature range of 225-240oC, corresponding to the over-aging reaction, has been established as transition temperature above which degradation of hardness was observed in Al-based alloys.
Mg alloys, QE22A, EV31A, ZE41A and WE43B, subjected to the same testing, showed an improved high temperature performance. ZE41A and WE43B alloys exhibited gradual softening with a hardness decrease from 80 to 70 HRB and from 80 to 60 HRB for EV31A and QE22A alloys. Dilatometer analysis revealed a visible transformation peak at 275oC in EV31A alloy, but no similar over-aging reactions were observed in other Mg alloys up to 400oC. Differences in performance between Al and Mg alloys have also been observed in tensile characteristics. In addition, the microstructural analysis has been carried out to understand the link between microstructure and mechanical properties at elevated temperatures.
Abstracts:
- Abstract AeroMat-Kasprzak et al.doc (0.0KB) - Abstract