Methods for depositing sacrificial coatings on aerospace components

A method for producing a protective coating on an aerospace component, comprising:

• depositing a metal oxide template layer on the aerospace component comprising nickel and aluminum by an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process, wherein the metal oxide template layer comprises chromium oxide and a metal oxide selected from tungsten oxide, molybdenum oxide, vanadium oxide, or any combination thereof;
• and
• heating the aerospace component containing the metal oxide template layer to a temperature of about 900° C. to about 1,200° C. during a thermal process comprising:
• diffusing aluminum contained within the aerospace component towards a surface of the aerospace component containing the metal oxide template layer;
• oxidizing the diffused aluminum to produce an aluminum oxide layer disposed between the aerospace component and the metal oxide template layer, wherein the aluminum oxide layer comprises α-Al2O3, wherein the metal oxide template layer and the aluminum oxide layer have a corundum crystal structure, and wherein the metal oxide template layer and the aluminum oxide layer have crystal structures with a lattice mismatch of about 0.1% to about 10%;
• and
• removing at least a portion of the metal oxide template layer while leaving the aluminum oxide layer by converting the chromium oxide to chromium oxide hydroxide during the thermal process.

A method for producing a protective coating on an aerospace component, comprising:

• depositing a metal oxide template layer on the aerospace component comprising nickel and aluminum by an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process, wherein the metal oxide template layer comprises chromium oxide and a metal oxide selected from tungsten oxide, molybdenum oxide, vanadium oxide, or any combination thereof;
• and
• powering a jet engine or a turbine containing the aerospace component while performing a thermal process, wherein thermal energy from the jet engine or the turbine heats the aerospace component and the metal oxide template layer to a temperature of about 900° C. to about 1,200° C. during the thermal process, where in the thermal process further comprises:
• diffusing aluminum contained within the aerospace component towards a surface of the aerospace component containing the metal oxide template layer;
• and
• oxidizing the diffused aluminum to produce an aluminum oxide layer disposed between the aerospace component and the metal oxide template layer, wherein the metal oxide template layer and the aluminum oxide layer have a corundum crystal structure, and wherein the metal oxide template layer and the aluminum oxide layer have crystal structures with a lattice mismatch of about 0.1% to about 10%.