Synthesis and Characterization of Mechanically Alloyed Ordered Intermetallic Materials
Abstract
This report summarizes our studies aimed at improving high temperature strength and creep resistance of mechanically alloyed (MA) intermetallics. MA and hot extruded NiAl was subjected to normal grain growth and secondary recrystallization (SRx) and the latter mechanism proved to significantly improve creep resistance. The minimum creep rate in SRx material was decreased one to two orders of magnitude in comparison to creep in the as-extruded condition. A different approach was to first synthesize NiAl powder containing AlN dispersion and then to fabricate composites containing Al2O3 fibers. The composite processed in the present study is one of the strongest NiAl-based alloys ever produced. In yet another attempt to optimize high temperature properties of intermetallics more refractory, Nb3Al - based materials were produced. It has been shown that mechanical alloying followed by hot pressing is a viable processing route for niobium aluminide intermetallics. The compressive strength of the examined materials was found to be superior to that in the NiAl, but the ductility was lower. The minimum creep rates were found to be approximately one order of magnitude less than those in MA NiAl. The creep rates in the present materials approach those in NASAIR 100, a first generation Ni-base single crystal superalloy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 30, 1997
- Accession Number
- ADA332498
Entities
People
- Hahn Choo
- Marek Dollar
- Philip Nash
- Soon-chul Ur
- Stan Dymek
Organizations
- Illinois Institute of Technology