Forming coating on metal substrate of thermochemical component e.g. turbine blade, by providing superalloy article, and forming metallic sub-layer by depositing platinum group metal on substrate layer and providing aluminum in vapor phase

摘要

The method comprises: providing a superalloy article (12); and forming a metallic sub-layer (13) by depositing a platinum group metal on a substrate layer and providing aluminum in a vapor phase. The platinum group metal is deposited with a thickness of 3-7 mu m. The vapor phase aluminum is prepared by a precursor containing aluminum in an atmosphere containing an active substance, which reacts with the precursor to form a gaseous aluminum compound. The method further comprises depositing a ceramic layer (14) on the metallic sub-layer. The method comprises: providing a superalloy article (12); and forming a metallic sub-layer (13) by depositing a platinum group metal on a substrate layer and providing aluminum in a vapor phase. The platinum group metal is deposited with a thickness of 3-7 mu m. The vapor phase aluminum is prepared by a precursor containing aluminum in an atmosphere containing an active substance, which reacts with the precursor to form a gaseous aluminum compound. The vapor phase aluminum is prepared at 900-1150[deg] C, and the precursor is cement containing 15-20 wt.% of aluminum. The substrate layer is heat treated at 1000-1100[deg] C for 60-120 minutes under controlled atmosphere free from oxygen. The method further comprises depositing a ceramic layer (14) on the metallic sub-layer. An independent claim is included for a thermochemical component.