A ceramic coating system using an atmospheric pressure plasma generator is provided, which includes a vacuum chamber configured to maintain a vacuum therein, a support disposed inside the vacuum chamber and fixedly supporting a substrate, a plasma generator that generates active species through plasma discharge and includes a nozzle part wherein at least a portion of the nozzle part is disposed to face the substrate inside the vacuum chamber, and a particle providing apparatus that transfers ceramic particles to one side of the nozzle part.

A manufacturing method is provided. During this method, a preform component is provided for a turbine engine. The preform component includes a substrate. A preform meter section and a preform diffuser section are formed in the substrate. An internal coating is applied to at least the preform meter section to provide a meter section of a cooling aperture. External coating material is applied over the substrate. The applying of the external coating material forms an external coating over the substrate. The applying of the external coating also builds up the external coating material within the preform diffuser section to form a diffuser section of the cooling aperture.

An article includes a body having a plasma-sprayed ceramic coating on a surface thereof. The body can be formed of at one least one of the following materials: Al, Al.sub.2O.sub.3, AlN, Y.sub.2O.sub.3, YSZ, or SiC. The plasma-sprayed ceramic coating can include at least one of Y.sub.2O.sub.3, Y.sub.4Al.sub.2O.sub.9, Y.sub.3Al.sub.5O.sub.12 or a solid-solution of Y.sub.2O.sub.3 mixed with at least one of ZrO.sub.2, Al.sub.2O.sub.3, HfO.sub.2, Er.sub.2O.sub.3, Nd.sub.2O.sub.3, Nb.sub.2O.sub.5, CeO.sub.2, Sm.sub.2O.sub.3 or Yb.sub.2O.sub.3. The plasma-sprayed ceramic coating can further include splats.

An article includes a body having a plasma-sprayed ceramic coating on a surface thereof. The body can be formed of at one least one of the following materials: Al, Al.sub.2O.sub.3, AlN, Y.sub.2O.sub.3, YSZ, or SiC. The plasma-sprayed ceramic coating can include at least one of Y.sub.2O.sub.3, Y.sub.4Al.sub.2O.sub.9, Y.sub.3Al.sub.5O.sub.12 or a solid-solution of Y.sub.2O.sub.3 mixed with at least one of ZrO.sub.2, Al.sub.2O.sub.3, HfO.sub.2, Er.sub.2O.sub.3, Nd.sub.2O.sub.3, Nb.sub.2O.sub.5, CeO.sub.2, Sm.sub.2O.sub.3 or Yb.sub.2O.sub.3. The plasma-sprayed ceramic coating can further include splats.

A coated article including an article having a surface; an oxidation resistant bond coat layer deposited on the surface, the oxidation resistant bond coat layer comprising a metal silicide phase, a crystalline ceramic phase and an amorphous ceramic phase, wherein the metal silicide phase has an aspect ratio greater than 1:1 but less than 50:1.

In some examples, an article for a high-temperature mechanical system including a substrate and a doped calcia-magnesia-alumina-silicate resistant (doped CMAS-resistant) layer on the substrate. The doped CMAS-resistant layer is a thermal barrier coating or an environmental barrier coating and includes a calcia dopant.

In some examples, an article for a high-temperature mechanical system including a substrate and a doped calcia-magnesia-alumina-silicate resistant (doped CMAS-resistant) layer on the substrate. The doped CMAS-resistant layer is a thermal barrier coating or an environmental barrier coating and includes a calcia dopant.

A seal system includes a ceramic component that has a non-core-gaspath surface region that defines a first surface roughness and a core gaspath surface region. A metallic component is situated adjacent the non-core-gaspath surface region. A coating system is disposed on the ceramic component. The coating system includes a silicon-containing layer on the non-core-gaspath surface region and a barrier layer that has a first section on the silicon-containing layer and a second section on the core-gaspath region and that is connected to the first section. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The first section is in contact with the metallic component and the second section serves as an environmental barrier on the core-gaspath region.

A steel piston with an engineered coating is provided. A high thermal conductivity material, for example copper, is disposed on first regions of a combustion bowl to reduce hot spots in the piston. A low thermal conductivity material, for example a ceramic, is disposed on second regions of the combustion bowl to reduce loss of heat through the piston. The high thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 5 μm to help reflect IR radiation and promote fuel flow. The low thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 3 μm to promote fuel flow. The low thermal conductivity material is also disposed on the bowl rim and top ring land, and has a surface roughness (R.sub.a) of greater than 8 μm on the bowl rim and top ring land to retard gas flow.

A steel piston with an engineered coating is provided. A high thermal conductivity material, for example copper, is disposed on first regions of a combustion bowl to reduce hot spots in the piston. A low thermal conductivity material, for example a ceramic, is disposed on second regions of the combustion bowl to reduce loss of heat through the piston. The high thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 5 μm to help reflect IR radiation and promote fuel flow. The low thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 3 μm to promote fuel flow. The low thermal conductivity material is also disposed on the bowl rim and top ring land, and has a surface roughness (R.sub.a) of greater than 8 μm on the bowl rim and top ring land to retard gas flow.