A method comprising: providing a first source able to supply aluminum content for a nickel aluminide based coating; providing a second source able to supply nickel and at least one alloy element content for the nickel aluminide based coating; providing a metallic substrate; disposing by a cathodic arc deposition process a nickel aluminide based coating precursor on at least a portion of the metallic substrate, the coating precursor comprising aluminum content provided by the first source, and nickel and at least one alloy element (24a, 24b) content provided by the second source; the process comprising: disposing a first layer of the coating precursor comprising an amount of nickel and at least one alloy element to overlie and be in contact with the metallic substrate utilizing the second source; thereafter disposing an intermediate layer of the coating precursor comprising an amount of aluminum to overlie and be in contact with the first layer utilizing the first source; and thereafter disposing a second layer of the coating precursor of nickel and at least one alloy element in contact with and overlying the intermediate aluminum layer utilizing the second source; the method further comprising forming the nickel aluminide based coating from the coating precursor, wherein the forming comprises subjecting the coating precursor to a heat treatment so as to interdiffuse the layers (24a,26,24b) to form the nickel aluminide based coating wherein the aluminum is diffused throughout a thickness of the coating, wherein the heat treatment includes heating to 1079°C (1975°F). providing a first source able to supply aluminum content for a nickel aluminide based coating; providing a second source able to supply nickel and at least one alloy element content for the nickel aluminide based coating; providing a metallic substrate; disposing by a cathodic arc deposition process a nickel aluminide based coating precursor on at least a portion of the metallic substrate, the coating precursor comprising aluminum content provided by the first source, and nickel and at least one alloy element (24a, 24b) content provided by the second source; the process comprising: disposing a first layer of the coating precursor comprising an amount of nickel and at least one alloy element to overlie and be in contact with the metallic substrate utilizing the second source; thereafter disposing an intermediate layer of the coating precursor comprising an amount of aluminum to overlie and be in contact with the first layer utilizing the first source; and thereafter disposing a second layer of the coating precursor of nickel and at least one alloy element in contact with and overlying the intermediate aluminum layer utilizing the second source; the method further comprising forming the nickel aluminide based coating from the coating precursor, wherein the forming comprises subjecting the coating precursor to a heat treatment so as to interdiffuse the layers (24a,26,24b) to form the nickel aluminide based coating wherein the aluminum is diffused throughout a thickness of the coating, wherein the heat treatment includes heating to 1079°C (1975°F). disposing a first layer of the coating precursor comprising an amount of nickel and at least one alloy element to overlie and be in contact with the metallic substrate utilizing the second source; thereafter disposing an intermediate layer of the coating precursor comprising an amount of aluminum to overlie and be in contact with the first layer utilizing the first source; and thereafter disposing a second layer of the coating precursor of nickel and at least one alloy element in contact with and overlying the intermediate aluminum layer utilizing the second source; the method further comprising forming the nickel aluminide based coating from the coating precursor, wherein the forming comprises subjecting the coating precursor to a heat treatment so as to interdiffuse the layers (24a,26,24b) to form the nickel aluminide based coating wherein the aluminum is diffused throughout a thickness of the coating, wherein the heat treatment includes heating to 1079°C (1975°F).