Work

Synchrotron quantification of graphite nodule evolution during the solidification of cast iron

Year: 2018

Type: article

Abstract: In cast iron, graphite develops in conjunction with the metallic matrix during solidification. The morphology and distribution of the embedded graphite is pivotal for mechanical properties from yield strength to fatigue. A novel high temperature environmental cell was developed and combined with in situ synchrotron tomography to investigate and quantify microstructural evolution, including graphite nodule nucleation and growth rates in ductile cast iron. The mechanisms of degenerate graphite nodule formation were also revealed. The formation of a coherent primary gamma phase dendritic network before the graphite nucleation is demonstrated. The graphite nodule nucleation rate, mobility and growth rates are compared to classical models, highlighting the limitations in these models. The results provide unique insights to tune the temperature pathways during cast iron solidification to achieve desired uniform rounded graphite morphologies and size distributions.

Source: Acta Materialia

DOI: 10.1016/j.actamat.2018.06.007

Authors: M.A. Azeem, M.K. Bjerre, R.C. Atwood, N. Tiedje, P.D. Lee

Institutions: Rutherford Appleton Laboratory, Research Complex at Harwell, University College London, Technical University of Denmark, Diamond Light Source

Language: English

Topic: Solidification and crystal growth phenomena

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,055