Abstract: This invention relates to coatings for a metal or non-metal substrate comprising (a) a thermal sprayed bondcoat layer applied to the substrate, and (b) a thermal sprayed ceramic layer applied to said bondcoat layer; wherein said coating has a helium leak rate of less than 6×10?6 standard cubic centimeters per second. The thermal sprayed bondcoat layer comprises (i) a thermal sprayed inner layer alloy, and (ii) a thermal sprayed outer layer alloy. The inner layer alloy is thermally sprayed from a powder having a mean particle size of 50 percentile point in distribution of from about 5 microns to about 50 microns. The outer layer alloy is thermally sprayed from a powder having a mean particle size of 50 percentile point in distribution of from about 30 microns to about 100 microns. The coatings are useful for extending the service life under severe conditions, such as those associated with metallurgical vessels' lances, nozzles and tuyeres.

Abstract: This invention relates to coatings for a metal or non-metal substrate comprising (a) a thermal sprayed bondcoat layer applied to said substrate, said bondcoat layer comprising: (i) a thermal sprayed inner layer comprising an inner layer alloy of MCrAlM? wherein M is an element selected from nickel, cobalt, iron and mixtures thereof, and M? is an element selected from yttrium, zirconium, hafnium, ytterbium and mixtures thereof; and (ii) a thermal sprayed outer layer comprising an outer layer alloy of MCrAlM? wherein M is an element selected from nickel, cobalt, iron and mixtures thereof, and M? is an element selected from yttrium, zirconium, hafnium, ytterbium and mixtures thereof, and (b) a thermal sprayed ceramic layer applied to said bondcoat layer. The coatings are useful for extending the service life under severe conditions, such as those associated with metallurgical vessels' lances, nozzles and tuyeres.