About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
|
Symposium
|
High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond IV
|
Presentation Title |
Understanding Oxidation Behavior and Microstructure Evolution of Si-based Coatings Formed on Refractory Multi-principal Element Alloys |
Author(s) |
Brady Bresnahan, David Poerschke |
On-Site Speaker (Planned) |
Brady Bresnahan |
Abstract Scope |
The large design space for refractory multi-principal element alloys (MPEAs) provides opportunities to tune alloy chemistry to simultaneously optimize the bulk and surface properties. This investigation studied Si-based coatings to improve the oxidation resistance of refractory alloys. A set of MPEAs systematically exploring composition variables related to silicide formation were produced by arc melting and modified by pack cementation. The effects of alloy and coating compositions on coating microstructure evolution at various temperatures were studied, with specific attention on understanding refractory metal partitioning between silicide phases. The phase evolution after oxidation was similarly explored where the tendency to form protective oxides, crack density under thermal cycling, and mass change were used to evaluate the composite material performance and understand composition effects. These insights will enable coupled alloy and process design to improve oxidation resistance while taking advantage of the superior high temperature yield strengths of refractory MPEAs for aerospace applications. |