Abstract: A method of forming a wall structure on a substrate comprises depositing, by additive-layer, powder-fed, laser-weld deposition apparatus, a plurality of material layers overlying one another on the substrate to form the wall structure. Each material layer of the plurality of material layers has (a) a layer thickness, measured in a direction locally perpendicular to a profile of the substrate, of no greater than about 350 ?m and (b) a layer width, measured in a direction locally parallel to the profile of the substrate, of no greater than about 1200 ?m.

Abstract: A gas shield arrangement for a gas turbine engine includes a first gas shield that is arranged to cover an inlet of a gas flow path of the gas turbine engine and a second gas shield that is arranged to cover a first outlet of the gas flow path of the gas turbine engine. The gas shield arrangement further includes a reservoir that holds fluid and a pump that pumps the fluid from the reservoir to one of a first valve and a second valve and that returns at least some of the pumped fluid to the reservoir from the other of the first valve and the second valve.

Abstract: A method of repairing a metallic component (formed from a first material) by powder feeding laser deposition, comprises the step of depositing a plurality of first repair layers onto a repair surface of the component to form a first repair zone, the first of the plurality of first repair layers comprising a mixture of A/B by weight of the first material and a second material, each nth successive one of the plurality of first repair layers comprising a change in the proportion of the second material in the mixture, the last of the plurality of first repair layers comprising a mixture of C/D by weight of the first material and the second material.

Abstract: A gas shield arrangement for a gas turbine engine, the gas shield arrangement comprising: a first gas shield arranged to cover an inlet of a gas flow path of the gas turbine engine; and a second gas shield arranged to cover a first outlet of the gas flow path of the gas turbine engine.

Abstract: A method of repairing a metallic component (formed from a first material) by powder feeding laser deposition, comprises the step of depositing a plurality of first repair layers onto a repair surface of the component to form a first repair zone, the first of the plurality of first repair layers comprising a mixture of A/B by weight of the first material and a second material, each nth successive one of the plurality of first repair layers comprising a change in the proportion of the second material in the mixture, the last of the plurality of first repair layers comprising a mixture of C/D by weight of the first material and the second material.