Applied Numerical Analysis. By C.F. Gerald. Pp. xii, 340. £3·60. 1970. (Addison-Wesley.)

Mechanical properties of structural materials strongly depend on their microstructure. The aim of this work, which essentially has an experimental character, is to correlate microstructure and mechanical properties of pearlitic gray cast iron. Because of the industrial interest behind to this work, the material under study is extracted from identical sand-cast parts produced by three different foundries. Laboratory tests show that mechanical properties, as tensile and fatigue strength, of gray cast iron of the same grade vary from foundry to foundry. A noticeable statistical data scatter is found also, depending on the location of the castings from which the specimens are machined. The cause of this behaviour is ascribed to the inhomogeneity that characterizes the gray cast iron microstructure. Metallographic sections are observed to quantitatively measure the relevant microstructural parameters, as graphite lamellas morphology, eutectic cell size and inclusions content. Results are correlated to the measured mechanical properties: reduced graphite content increases the tensile and the fatigue strength, both fine eutectic cells structure and high eutectic phosphide percentage improve the fatigue properties.

Microstructure and mechanical properties of pearlitic gray cast iron

Effect of copper and silicon content on mechanical properties in Al–Cu–Si–Mg alloys

Human civilization has evolved from the Stone Age, through the Bronze Age to reach the Iron Age around 1500 B.C. There are many to contend that today we are living in the age of engineered materials, yet the importance of iron castings continues to support the thesis that we are still in the Iron Age. Cast iron, the first man-made composite, is at least 2500 years old. It remains the most important casting material, with over 70% of the total world tonnage. The main reasons for cast iron longevity are its wide range of mechanical and physical properties coupled with its competitive price. This paper is a review of the fundamentals of solidification of iron-base materials and of the mathematical models that describe them, starting with the seminal paper by Oldfield, the first to attempt modeling of microstructure evolution during solidification, to the prediction of mechanical properties. The latest analytical models for irregular eutectics such as cast iron as well as numerical models with microstructure output are discussed. However, since the space does not permit an extensive description of the multitude of models available today, the emphasis is on model performance rather than the mathematics of model formulation. Also, because of space constrains, white iron and defect occurrence will not be covered.

http://mohsenorama.persiangig.com/87/solidification%20and%20modeling%20of%20cast%20iron.pdf

Solidification and modeling of cast iron—A short history of the defining moments

Development of wear resistant carbidic austempered ductile iron (CADI)

Solidification of gray cast iron

Examination of the solidification macrostructure of spheroidal and flake graphite cast irons using DAAS and ESBD

The effectiveness of several metallographic techniques used to reveal the solidification structure of nodular iron has been evaluated by quantitative metallography. A colour metallography reagent, ...

Revealing the solidification structure of nodular iron

This study deals with the solidification and microsegregation processes of near eutectic ductile cast iron. A detailed analysis of old and new solidification models was made. Metallographic techniques, developed elsewhere by the authors, were used to reveal the solidification microstructure and macrostructure. The results allow a new solidification model to be proposed, where each solidification unit is a grain of eutectic austenite that has a dendritic substructure and contains a very large number of graphite nodules. A pattern of microsegregation exists inside each solidification grain, while no intergranular microsegregation has been detected. A procedure to characterise the solidification refinement was developed considering the location of the last to freeze areas.

Revealing and characterising solidification structure of ductile cast iron

Recently, the scientific community has begun to study in detail the potential application of ductile iron in the production of thin wall components. Efforts are focused on the identification of the operative conditions necessary to obtain parts free of defects, with the desired microstructure. These aspects have been widely examined in the past for parts of conventional thickness (more than 5 mm), either experimentally or by using computational programs to model the solidification process. Nevertheless, modeling of thin walled parts is still unreliable, since specific databases are not available. The objective of this work is to study the evolution of the graphite nodule count and shape in ductile iron, as the section thickness diminishes down to 1.5 mm, using conventional casting procedures and resin bonded sand molds. A reasonably accurate correlation between solidification time and nodule count has been developed, based on experimental and modeled cooling curves. The morphology of graphite nodules has been characterized by image analysis, and the results correlated with the solidification time. The advantages of using solidification time as a parameter instead of thickness are also discussed.

https://www.jstage.jst.go.jp/article/isijinternational1989/42/3/42_3_257/_pdf

Roberto Enrique Boeri

Papers

Solidification of gray cast iron

Examination of the solidification macrostructure of spheroidal and flake graphite cast irons using DAAS and ESBD

Revealing the solidification structure of nodular iron

Revealing and characterising solidification structure of ductile cast iron

Shape and Count of Free Graphite Particles in Thin Wall Ductile Iron Castings