Chapters authored
‘Vari-Morph’ (VM) Cast Iron with Several Forms of Graphite: Technology, Properties, Application
Cast iron with mixed-shape graphite and controlled fractions of individual shapes, known as VM cast iron (‘Vari - Morph’), can become material for castings with special requirements. The name of the cast iron ‘Vari Morph’ (VM) was first proposed by the authors in 2018 at the World Congress of Foundries in Krakow. VM cast iron displays physical and mechanical properties, which cannot be achieved with homogeneously shaped graphite. Cast iron with (L – flake) + (V – vermicular) graphite is characterised by good thermal conductivity and better A5 (elongation) and Rm (tensile strength) (than grey cast iron. What is of particular interest is cast iron with a mixed form: (S – spheroidal) + (V – vermicular). Currently, research is being carried out to achieve cast iron with a high-quality index (QI) defined as Rm/HB. This paper presents the results of research of physical (thermal conductivity), mechanical (Rm and A5) and functional properties (thermal fatigue) of VM cast iron. The ultrasound technique was applied for assessing the graphite compactness degree (ξ): ultrasonic wave speed CL = f(ξ), damping factor α = f(ξ). The article also presents the correlations between the above-mentioned parameters, as well as describes the technology used to produce VM cast iron and possible areas of application of the material.
Part of the book: Casting Processes