Method of forming protective coating

A method of forming a protective coating, the method comprising:

• providing a substrate comprising at least one chemical element and a surface;
• forming a basecoat composition comprising an aluminium phase comprising aluminium, wherein forming the basecoat further comprises
• forming a solution comprising phosphoric acid;
• adding aluminium hydroxide to the solution;
• adding the aluminium phase to the solution;
• and
• stirring the solution to obtain the basecoat composition comprising aluminium hydrogen phosphate and the aluminium phase;
• applying the basecoat composition on the surface of the substrate to form a basecoat layer;
• heating the basecoat layer to a first temperature (T1) for a predetermined period of time;
• applying a glow discharge plasma on the basecoat layer;
• heating the basecoat layer to a second temperature (T2) greater than the first temperature (T1), in order to activate an exothermic reaction between at least the aluminium phase of the basecoat layer and the at least one chemical element of the substrate, wherein the exothermic reaction forms the protective coating on the surface of the substrate;
• and
• removing a plurality of projections extending from a major surface of the protective coating, wherein the plurality of projections is formed during the exothermic reaction.

A method of forming a protective coating, the method comprising:

• providing a substrate comprising at least one chemical element and a surface;
• forming a basecoat composition comprising an aluminium phase comprising aluminium;
• applying the basecoat composition on the surface of the substrate to form a basecoat layer;
• heating the basecoat layer to a first temperature (T1) for a predetermined period of time;
• applying a glow discharge plasma on the basecoat layer;
• heating the basecoat layer to a second temperature (T2) greater than the first temperature (T1), in order to activate an exothermic reaction between at least the aluminium phase of the basecoat layer and the at least one chemical element of the substrate, wherein the exothermic reaction forms the protective coating on the surface of the substrate;
• and
• treating the aluminium phase with a halide-based wash coat solution prior to adding the aluminium phase to the solution.