Study of Plasma Spray Alumina -Aluminide Composite Coating on Metals

Abstract

The investigation is devoted to development of nickel aluminide and iron aluminide coatings on various metal substrates viz. aluminium, mild steel, stainless steel and copper, using locally available and commercial grade aluminum, nickel and iron powders. Duplex structures involving aluminium oxide (alumina) coating over these aluminide bond coatings have also been developed and characterized. Plasma spraying was carried out using the 40kW atmospheric plasma spray system. Input DC power to the plasma torch was varied from 10 kW to 20 kW by controlling the arc current. In order to study the in-flight reaction nickel/iron and aluminium, a set of spheroidization experiments is carried out under identical conditions.