THIN WALL DUCTILE IRON (TWDI) AND AUSTEMPERED DUCTILE IRON (TWADI) CASTINGS

Abstract

There are 3 major challenges that face automotive manufacturers: emissions control, cost manufacture reduction and fuel economy improvement. When thin wall ductile iron casting was introduced to be used for automotive industry, there were many problems experienced in trying to produce it. This research aims at investigating metallurgical and technological parameters involved in the production of thin wall and light weight iron castings (3mm) for automotive applications. Two grades of iron will be studied i.e. ductile iron (DI) and austemeperd ductile iron (ADI) castings. Parameters to be studied will include: the chemical composition of the iron alloys, the melting and the molten treatment, the solidification rate and the molding techniques (green sand, green sand + 10% insulation material and investment castings), and the austempering treatment for ADI. This study will cover the effect of the rate of cooling on the matrix structure and the mechanical properties of DI & ADI castings as well as the influence of the austempering temperature on the mechanical properties of ADI.