On the use of heterogeneous thermomechanical and thermophysical material properties in finite element analyses of cast components

Johan Jansson,Kent Salomonsson,Jakob Olofsson

doi:10.1088/1757-899x/529/1/012076

Johan Jansson, Kent Salomonsson + Show 1 more

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https://doi.org/10.1088/1757-899x/529/1/012076

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Abstract

Cast components generally show a heterogeneous distribution of material properties, caused by variations in the microstructure that forms during solidification. Variations caused by the casting process are not commonly considered in structural analyses, which might result in manufacturing of sub-optimised components with unexpected in-use behaviour. In this paper, we present a methodology which can be used to consider both thermomechanical and thermophysical variations using finite element analyses in cast components. The methodology is based on process simulations including microstructure modelling and correlations between microstructural features and material properties. Local material data are generated from the process simulation results, which are integrated into subsequent structural analyses. In order to demonstrate the methodology, it is applied to a cast iron cylinder head. The heterogeneous distribution of material properties in this component is investigated using experimental methods, demonstrating local variations in both mechanical and physical behaviour. In addition, the strength-differential effect on tensile and compressive behaviour of cast iron is considered in the modelling. The integrated simulation methodology presented in this work is relevant to both design engineers, production engineers as well as material scientists, in order to study and better understand how local variations in microstructure might influence the performance and behaviour of cast components under in-use conditions.

Highlights

Numerical methods such as Finite Element Analyses (FEA) and topology optimization are commonly used by engineers in order to design and optimize cast components towards high load bearing capacity while simultaneously minimizing weight
Variations caused by the casting process are not commonly considered in structural analyses, which might result in manufacturing of sub-optimised components with unexpected in-use behaviour
During the solidification of pearlitic hypo-eutectic flake graphite cast iron, a dendritic austenite structure grows as the primary phase, with features governed by the chemical composition and the inoculation conditions [1]

Summary

Introduction

Numerical methods such as Finite Element Analyses (FEA) and topology optimization are commonly used by engineers in order to design and optimize cast components towards high load bearing capacity while simultaneously minimizing weight. During the solidification of pearlitic hypo-eutectic flake graphite cast iron, a dendritic austenite structure grows as the primary phase, with features governed by the chemical composition and the inoculation conditions [1]. Graphite is precipitated together with eutectic austenite in a eutectic reaction, where the local composition, cooling- and inoculation conditions determine the morphology of the graphite as well as the size of the eutectic cells [2, 3]. These features have been studied and correlated to both mechanical and physical material properties in several works.

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