Studies on the Factors Influencing the Quality of Aluminium Alloys in Lost Foam Casting Process

摘要

There is an increasing interest in Lost Foam Casting technique because of its ability to produce near-net-shaped components of high complexity with eco-friendly nature. In Lost Foam Casting (LFC), foamed polystyrene pattern (Thermocole) is prepared along with sprue, runner and gating system coated with water-based refractory slurry, dried and contained in a moulding box filled with dry free-flow silica sand that is compacted through vibration. The foam pattern undergoes thermal degradation and is gradually replaced by liquid metal. This paper deals with the studies on the various parameters which influence the quality of aluminium alloy (LM6) casting in Lost Foam Casting process. The quality of the Lost Foam Casting process is strongly affected by the elimination of the degradation product which in turn depends on various parameters - four parameters such as refractory coating grain size, permeability of moulding sand, moulding box size and gating system. These four parameters with three levels are considered and experiments are conducted based on L9 Orthogonal Array (OA) using Taguchi technique. Density is considered as quality characteristics and the density of each castings are measured. The results show that the refractory coating grain size and permeability of moulding sand are mainly influencing the quality of castings.