A housing for a turbomachine includes a support sleeve extending along a central axis of the turbomachine and a volute portion defining a duct in the housing. The support sleeve and the volute portion together include a plastic substrate and metal plating disposed on at least a portion of an outer surface of the plastic substrate. The plastic substrate includes a matrix material and fibers embedded in the matrix material. The fibers have a first coefficient of thermal expansion. The metal plating has a second coefficient of thermal expansion. The fibers are selected such that a bulk coefficient of thermal expansion of the plastic substrate at the outer surface of the plastic substrate substantially matches the second coefficient of thermal expansion of the metal plating.

Various aspects include a composite turbomachine component and related methods. In some cases, a method includes: identifying a location of potential or actual structural weakness in a body of a turbomachine component, the body including a first material having a first thermal expansion coefficient; forming a slot in the location of the body, the slot extending at least partially through a wall of the turbomachine component; and bonding an insert to the body at the slot to form a composite component, the insert including a second material having a second thermal expansion coefficient differing from the first thermal expansion coefficient by up to approximately ten percent, the second material consisting of a nickel-chromium-molybdenum alloy, wherein after the bonding the insert is configured to reduce the potential or actual structural weakness in the body.

An angular pitch control ring (8) of stator vanes (2), the rotations of which are controlled by a mechanism (6) applying a thrust tangent to the ring (8), is also moved in translation when it is displaced, making it touch the stator (2). According to the invention, one lateral region (13) on one side of the mechanism (6) is constructed to be stiffer than the other region to take account of the larger forces that the mechanism (6) must apply in a direction of movement. Application to turbomachines.

A seal system a ceramic component having a surface region defining a first surface roughness, a metallic component situated adjacent the surface region, and a coating system disposed on the surface region. The coating system includes a silicon-containing layer on the surface region and a barrier layer on the silicon-containing layer. The silicon-containing layer has a surface in contact with the barrier layer. The barrier layer has a surface in contact with the metallic component. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The barrier layer limits interaction between silicon of the silicon-containing layer and elements of the metallic component. The barrier layer has a coefficient of thermal expansion that is within about 60% of a coefficient of thermal expansion of the ceramic component. A gas turbine engine and a method are also disclosed.

A heat shield for polymer matrix composite material structure including at least one layer of polymer matrix composite material comprising materials made up of fibers that are embedded in an organic polymer matrix, the at least one layer having a first side opposite a second side; and a heat shield in operative communication with the at least one layer of polymer matrix composite material, wherein the heat shield comprises a material composition thermally resistant to a thermal energy sufficient to degrade the polymer matrix composite material structure.