|About this Abstract
||MS&T23: Materials Science & Technology
||Advances in Understanding of Martensite in Steels II
||Low Temperature Martensitic Transformations in Fe-Ni Alloys: Insight from Iron Meteorite Analyses
||Frederic Danoix, Raphaele Danoix, Fabien Cuvilly, Jerome Gattacceca, Clara Maurel, Matthieu Gounelle, Mathieu Roskosz, Louna Perez, Mohamed Gouné
|On-Site Speaker (Planned)
Metal matrix in iron meteorites are (roughly) bulk iron nickel alloys containing up to 35at%Ni. The initial metal alloy was melted in the core of early formed planetesimals, and was cooled at extremely low rates (measured in kelvin per million year) from austenite though a ferrite-austenite dual phase region.
During cooling, the main transformation is the precipitation of Widmanstätten ferrite from austenite, generating the iconic microstructures of metallic meteorites. As it develops, the ferrite rejects nickel towards the austenite. In the highest nickel regions, austenite is stabilized down to very low temperatures, and may eventually transform to martensite with further cooling.
The presence of martensite in meteorites with different microstructures is thus an element to retrieve their thermal and mechanical history, and thus an invaluable source of information regarding the early solar system history.