Patent ID: 11952317
Assignee: ROLLS-ROYCE PLC
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  F | IPC C  F

Claim 0:
1. An article comprising:
a substrate of a gas turbine engine component;
and a barrier coating on the substrate, the barrier coating comprising:
a matrix comprising a rare-earth disilicate, the matrix extending from an inner interface facing the substrate to an outer surface opposite the inner interface;
and a graded volumetric distribution of rare-earth oxide rich (REO-rich) phase regions in the matrix along a direction from the inner interface to the outer surface,
wherein the REO-rich phase regions define bands in predetermined locations within the matrix,
wherein the REO-rich phase regions include rare-earth oxide in excess of stoichiometric rare-earth monosilicate,
wherein the matrix has a higher porosity in the first region nearer the outer surface than in the second region nearer the inner interface; wherein the barrier coating defines a coating thickness along the direction from the outer surface to the inner interface,
wherein the first region defines a first thickness along the direction, wherein the second region defines a second thickness along the direction, and wherein a ratio of the first thickness to the coating thickness is greater than 0.1, and
wherein a ratio of the second thickness to the coating thickness is greater than 0.1.