A component for a gas turbine engine is described. The component may comprise a body portion formed from a metallic material. The component may further comprise an abrasive surface forming at least one surface of the body portion, and the abrasive surface may be configured to abrade an abradable material. The abrasive surface may be formed from electrical discharge machining of the metallic material.

A piston ring with a coated outer surface is provided. The coating is disposed on end sections of the outer surface adjacent a gap. Typically, a middle section of the outer surface located between the end sections is not coated. The coating can be formed of CrN or DLC, and the CrN coating can be applied by physical vapor deposition (PVD). The end sections of the outer surface, upon which the coating is applied, are rough. For example, the outer surface can be blasted or otherwise textured to achieve the rough surface. The rough surface retains oil and distributes stress better than a smooth surface, and thus reduces crazing and flaking of the coating.

A method for producing a selective diamond-coated substrate, wherein the diamond-coated substrate includes: a substrate having surfaces including cemented carbide material, areas selected to be coated, and areas not selected to be coated; and one or more diamond coatings on the areas selected to be coated, the method including following steps in order: a first masking step, wherein the areas not selected to be coated but could be chemically attacked during a chemical pre-treatment step, are masked by applying a latex-mask covering these areas; one or more chemical pre-treatment steps; a mask-removing step, wherein the latex-mask is removed; a second masking step, wherein the areas of the substrate surfaces from which the latex-mask was removed and not selected to be coated but could be coated with one or more diamond coatings during one or more coating steps, are covered with one or more masking-covers; and one or more coating steps.

A metallic foil for lightning strike protection in a composite aerospace structure having a length, a width, and a thickness of not more than 30 microns. There are a plurality of pores of a predefined geometric shape extending through the thickness of the metallic foil and being distributed across a surface area defined by the length and the width of the metallic foil. The plurality of pores in the aggregate define an open area of not more than 40% of the surface area and the metallic foil has a weight of not more than 115 g/m.sup.2. The metallic foil has a weight to conductivity ratio of not more than 0.40 gram-ohms per square.

A tribological system, comprising a main body and a sandwich lubrication, in which the sandwich lubrication includes a binder-free solid lubricant layer comprising a solid lubricant, and a lubricant layer comprising a lubricant. The binder-free solid lubricant layer and the lubricant layer are present as separate layers on the main body and wherein the mass ratio of solid lubricant to lubricant is at most 0.05:1.

A tribological system, including a main body and a sandwich lubrication, wherein the sandwich lubrication includes a binder-free solid lubricant layer including a solid lubricant, and a lubricant layer including a lubricant. The binder-free solid lubricant layer and the lubricant layer are present as separate layers on the main body and the mass ratio of solid lubricant to lubricant is at most 0.05:1. The solid lubricant includes polytetrafluoroethylene (PTFE), metal sulfide, graphite, graphene, boron nitride (hexagonal), calcium phosphate, silicate, layered silicate, or mixtures thereof.

An abrasion-resistant and friction-reduced coating for metal components is provided. The coating includes an inner layer, an intermediate layer and an outer layer. The inner layer is intended to be applied to the metal component and has at least one layer selected from: a metal layer, a metal-carbide layer, a metal-nitride layer, a metalcarbide- nitride layer and a metal-containing hydrocarbon layer. The intermediate layer includes at least one layer of amorphous carbon and the outer layer includes a WC:H layer or a a-C:H* layer. A maximum layer thickness of the coating is at most 5 m. The coating is suitable in particular as a piston coating for use in internal combustion engines.

A manufacturing method of a crystallized metal oxide layer includes: providing a substrate; forming a first insulation layer on the substrate; forming a first metal oxide layer on the first insulation layer; forming a second metal oxide layer on the first insulation layer; forming a second insulation layer on the first metal oxide layer and the second metal oxide layer; forming a silicon layer on the second insulation layer; performing a first laser process on a portion of the silicon layer covering the first metal oxide layer; and performing a second laser process on a portion of the silicon layer covering the second metal oxide layer. An active device and a manufacturing method thereof are also provided.

Multispectral optical interference coatings and methods. In one example, an optical element includes a substrate having a first surface and a second surface disposed opposite the first surface, a first multi-layer dielectric film disposed on the first surface of the substrate and constructed and arranged to transmit light in a first band of wavelengths, a second multi-layer dielectric film disposed on the second surface of the substrate and constructed and arranged to transmit light in a second band of wavelengths, the first and the second bands of wavelengths at least partially overlapping, and a bilayer diamond-like carbon (DLC) coating disposed on the first multi-layer dielectric film, the bilayer DLC coating including a first layer and a second layer, the first layer having a modulus of elasticity of a first value, and the second layer disposed on the first layer and having a modulus of elasticity of a second value that is greater than the first value.

A lubricant free firing weapon is provided having amorphous, solid, diamond-like carbon coating (DLC) containing sp3, sp2 carbons and hydrogen bonded to the metallic operating parts. Such firing weapons may further include physical modifications to the bolt carrier rails to enhance the expulsion of sand/dust on the bolt carrier under extreme environments. Also provided herein are plasma enhanced chemical vapor deposition processes for producing such lubricant free weapons having coat thicknesses of 1 m-25 m which allows for reliable operation under all environmental conditions including extreme environments such as hot/cold and sand/dust without the need for lubrication.