3D characterization of structure and micro-porosity in two cast irons with spheroidal graphite

• Published in: Materials characterization Vol. 158; p. 109991
• Main Authors: Lekakh, Simon N., Zhang, Xueliang, Tucker, Wesley, Lee, Hyoung K., Selly, Tara, Schiffbauer, James D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-12-2019
• Subjects: 3D scanning; Cast iron; Micro-porosity; Solidification; Spheroidal graphite; Structure; Spheroidal graphite; Structure; Cast iron; 3D scanning; Solidification; Micro-porosity
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2019.109991

Formation of low density graphite phase during solidification increases the volume of semi-solid cast iron with spheroidal graphite (SGI) and resulted pressure could help eliminate shrinkage micro-porosity in casting. Therefore, micro-porosity in casting can be linked to 3D graphite nodule structure. Two experimental SGI's with different levels of shrinkage micro-porosity in castings were intentionally produced by variation in inoculation parameters which influenced graphite nodule structure. 3D-morphological characteristics of graphite nodules and micro-porosity level were determined by μCT scanning. The obtained statistical data was discussed with respect to graphite nodule solidification mode and casting soundness. The capabilities of μCT scanning in predicting micro-shrinkage in SGI casting were compared to the other traditionally used techniques.
•Two experimental cast irons with spherical graphite were prepared applying different inoculation methods.•Micro-CT scanning of experimental castings was performed targeting graphite nodule and micro-porosity.•Graphite nodule diameter and space distribution were statistically evaluated and linked micro-porosity.•Different methods of structure evaluation of cast iron with spherical graphite were compared.