Directional solidification of compacted graphite iron - CGI

• Grant number: 13/18545-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2014
• End date: January 31, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: José Eduardo Spinelli
• Grantee: Thiago Sartorello Spinola
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The properties of the compact graphite iron (CGI) remain between those reported for the spheroidal graphite iron (SGI) and for the lamellar graphite iron (LGI), which means that shape of graphite plays an essential role on the final performance of such cast irons. The well-known versatility of properties of cast irons deserves strong interest of automotive industry concerning both research and technological development fields. Certain difficulties during processing of CGI are reported especially due to the need of a narrow control of Mg containing in order to produce an acceptable structure. The directional solidification systems allow, for instance, the determination of the microstructure evolution against the solidification thermal parameters, like cooling rate. The solidified castings and their structural features may be correlated with such process parameters. Some features include graphite shape, nodularity index, graphite size, length of the columnar region and carbide presence. This work aims to determine the aforementioned correlations for a Mg-modified and a non-modified cast iron. The results will include: Brinell hardness, ultimate and yield tensile strengths, plasticity, a complete characterization of the second phases like carbides and graphites. Further, the columnar-to-equiaxed transition (CET) will be investigated in both evaluated Fe-C alloys.