Mould materials used in flask investment casting of non-ferrous alloys

In the present project, the effect of mould materials on the metallurgical characteristics of castings produced by flask mould investment process are investigated. Investment moulds are required to have high chemical and physical (dimensional) stability, sufficient permeability and low surface roughness. These properties are closely related to the characteristics of mould materials. Investment materials are divided into two categories depending on the application temperature; first group is used up to 1200 °C and the second group can be employed at temperatures of 1800 °C. The main aim of the current project is to establish the relationship between the casting quality and the mould material characteristics. For this purpose, models for tensile, gravity and surface roughness specimens were prepared in accordance with the standarts and these models were moulded by using low temperature block mould investment process. Specimens were subsequently cast using 92.5 % Ag-7.5 % Cu alloy and santrifuge process. After the completion of casting process, specimens were tested and the results were analysed. The initial results illustrate that investment material variables play the most important role on the quality of cast products.