Turbine engine (80) components, such as blades (92), vanes (104, 106), ring segment 110 abradable surfaces 120, or transitions (85), have furcated engineered groove features (EGFs) (403, 404, 418, 509, 511, 512) that cut into the outer surface of the component's thermal barrier coating (TBC). In some embodiments, the EGF planform pattern defines adjoining outer hexagons (560, 640, 670, 690, 710). In some embodiments, the EGF pattern further defines within each outer hexagon (560, 640, 670, 690, 710) a planform pattern of adjoining inner polygons (570, 580, 590, 600, 610, 680, 682, 700, 702, 704, 705, 720). At least three respective groove segments (509, 511, 512) within the EGF pattern (506, 507, 508) converge at each respective outer hexagonal vertex (510, 564) or inner polygonal vertex (574, 564, 604, 614) in a multifurcated pattern, so that crack-inducing stresses are attenuated in cascading fashion, as the stress (σ.sub.A) is furcated (σ.sub.B, σ.sub.C) at each successive vertex juncture.

The present invention concerns a method for modifying the properties of the surface (F) of a material. The method comprises the following steps: preparing a first layer (12; 12) comprising an electrically conductive material suited to serve the function of a cathode, a second layer (14) comprising an electrically conductive material suited to serve the function of an anode and an intermediate layer (16) suited to become impregnated with an electrolyte in the liquid phase or to regulate its flow between said cathode and said anode; associating an electrolyte in the liquid phase with one or more of said layers (12, 14, 16); positioning the anode or the cathode on the surface (F) to be treated; supplying power to the cathode and the anode in order to activate the electrochemical process of the electrolyte in the liquid phase for a predetermined time interval.

To provide a sliding member having improved wear resistance, and a method of manufacturing the sliding member. A femoral head ball according to an aspect of the present disclosure includes a composite ceramic containing alumina and at least one oxide other than alumina. A surface roughness Ra of the sliding surface when the femoral head ball slides against a constituent member constituting an artificial joint is not more than 0.01 μm. The sliding surface includes a plurality of recessed portions each having an opening diameter of not more than 2 μm.

To provide a sliding member having improved wear resistance, and a method of manufacturing the sliding member. A femoral head ball according to an aspect of the present disclosure includes a composite ceramic containing alumina and at least one oxide other than alumina. A surface roughness Ra of the sliding surface when the femoral head ball slides against a constituent member constituting an artificial joint is not more than 0.01 μm. The sliding surface includes a plurality of recessed portions each having an opening diameter of not more than 2 μm.

A method for processing a component is provided and includes masking a first portion of the component with a maskant. The maskant includes a slurry having a plurality of particles in a fluid carrier. The plurality of particles comprises at least one of silicon, carbon, one or more rare earth disilicates, monosilicates or oxides, and combinations thereof. The method includes depositing a silicon-based coating on a second portion of the component via a chemical vapor deposition process and removing the maskant and any overlying silicon-based coating from the first portion of the component.

A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

An article includes a ceramic material and features a machined surface that is characteristic of cold ablation laser machining, and the machined surface exhibits no visible oxidation. A laser machining apparatus and technique is based on cold-ablation, but is modified or augmented with an inert assist gas to minimize deleterious surface modifications and mitigate oxide formation associated with laser machining.

An article includes a ceramic material and features a machined surface that is characteristic of cold ablation laser machining, and the machined surface exhibits no visible oxidation. A laser machining apparatus and technique is based on cold-ablation, but is modified or augmented with an inert assist gas to minimize deleterious surface modifications and mitigate oxide formation associated with laser machining.

A ceramic core (40) for an investment casting process (80) including a subsurface internal channel (50) for the introduction of leachate (98) to improve the effectiveness of a leaching process used to remove the core (94) from a cast alloy component (100). The subsurface internal channel may be completely hollow, or it may include one or more ribs (54). The core may be formed (82) using a 3D printing process wherein a carrier material (68) is deposited in a central region of the channel for the purpose of supporting an overlying layer (62) of core material, with the carrier material later being removed to reveal the hollow internal channel (52).