A rotor assembly for a gas turbine engine comprising: a rotor including a hub carrying one or more rotatable blades, the rotor mechanically attached to a shaft; and an annular seal carried by the shaft, wherein the annular seal comprises: a substrate; and a first layer disposed on the substrate, the first layer being a layer of copper alloy; characterised in that: the annular seal further comprises a second layer disposed as a film on the first layer and arranged to establish a sealing relationship with the rotor, the second layer comprising a solid lubricant comprising molybdenum disulfide, wherein the second layer has a lesser hardness than the first layer, wherein the second layer abuts against an inner diameter portion of the hub along an interface; and the hub includes a third layer deposited on surfaces of the inner diameter portion of the hub along the interface to establish a seal land and establish a sealing relationship between the second layer and the hub along the interface, the third layer being a solid lubricant comprising molybdenum disulfide. a rotor including a hub carrying one or more rotatable blades, the rotor mechanically attached to a shaft; and an annular seal carried by the shaft, wherein the annular seal comprises: a substrate; and a first layer disposed on the substrate, the first layer being a layer of copper alloy; characterised in that: the annular seal further comprises a second layer disposed as a film on the first layer and arranged to establish a sealing relationship with the rotor, the second layer comprising a solid lubricant comprising molybdenum disulfide, wherein the second layer has a lesser hardness than the first layer, wherein the second layer abuts against an inner diameter portion of the hub along an interface; and the hub includes a third layer deposited on surfaces of the inner diameter portion of the hub along the interface to establish a seal land and establish a sealing relationship between the second layer and the hub along the interface, the third layer being a solid lubricant comprising molybdenum disulfide. a substrate; and a first layer disposed on the substrate, the first layer being a layer of copper alloy; characterised in that: the annular seal further comprises a second layer disposed as a film on the first layer and arranged to establish a sealing relationship with the rotor, the second layer comprising a solid lubricant comprising molybdenum disulfide, wherein the second layer has a lesser hardness than the first layer, wherein the second layer abuts against an inner diameter portion of the hub along an interface; and the hub includes a third layer deposited on surfaces of the inner diameter portion of the hub along the interface to establish a seal land and establish a sealing relationship between the second layer and the hub along the interface, the third layer being a solid lubricant comprising molybdenum disulfide. the annular seal further comprises a second layer disposed as a film on the first layer and arranged to establish a sealing relationship with the rotor, the second layer comprising a solid lubricant comprising molybdenum disulfide, wherein the second layer has a lesser hardness than the first layer, wherein the second layer abuts against an inner diameter portion of the hub along an interface; and the hub includes a third layer deposited on surfaces of the inner diameter portion of the hub along the interface to establish a seal land and establish a sealing relationship between the second layer and the hub along the interface, the third layer being a solid lubricant comprising molybdenum disulfide.