Systems and methods are provided for applying cold spray erosion protection to an airfoil. One embodiment is a method for applying an abrasion coating to a fiber-reinforced composite substrate. The method includes applying a bond layer to the fiber-reinforced composite substrate by emitting, with a supersonic nozzle of a High Pressure Cold Spray (HPCS) system, a first gas stream including a first metal powder at a first speed below supersonic speed. The method further includes applying a cold spray deposit layer to the bond layer by emitting, with the supersonic nozzle, a second gas stream including a second metal powder at a second speed above supersonic speed.

Multiple processes for preparing porous articles are described. The porous articles can be in a wide array of shapes and configurations. The methods include providing a soluble material in particulate form and forming a packed region from the material. The methods also include contacting a flowable polymeric material with the packed region such that the polymeric material is disposed in voids in the packed region. The polymeric material is then at least partially solidified. The soluble material is then removed such as by solvent washing to thereby produce desired porous articles. Also described are systems for performing the various processes.

Multiple processes for preparing porous articles are described. The porous articles can be in a wide array of shapes and configurations. The methods include providing a soluble material in particulate form and forming a packed region from the material. The methods also include contacting a flowable polymeric material with the packed region such that the polymeric material is disposed in voids in the packed region. The polymeric material is then at least partially solidified. The soluble material is then removed such as by solvent washing to thereby produce desired porous articles. Also described are systems for performing the various processes.

Methods for producing a nanotextured surface on a substrate include forming nanoparticles from a precursor within a stream of a carrier gas. Methods include heating a surface of a substrate facing the carrier gas. Methods comprise delivering the nanoparticles to the surface of the substrate facing the carrier gas to produce the nanotextured surface.

In some examples, a method comprising: controlling a first ratio of a first liquid to a second liquid to form a first suspension comprising a powder and a first carrier liquid composition comprising at least one of the first liquid or the second liquid; directing the first suspension comprising the first carrier liquid and the powder to a plume of a thermal spray device; forming a first portion of a coating comprising the powder on a substrate from the first suspension; controlling a second ratio of the first liquid to the second liquid to form a second suspension comprising a second carrier liquid composition and the powder; directing the second suspension comprising the second carrier liquid composition and the powder to the plume of the thermal spray device; and forming a second portion of the coating comprising the powder on the substrate from the second suspension.

In some examples, a method comprising: controlling a first ratio of a first liquid to a second liquid to form a first suspension comprising a powder and a first carrier liquid composition comprising at least one of the first liquid or the second liquid; directing the first suspension comprising the first carrier liquid and the powder to a plume of a thermal spray device; forming a first portion of a coating comprising the powder on a substrate from the first suspension; controlling a second ratio of the first liquid to the second liquid to form a second suspension comprising a second carrier liquid composition and the powder; directing the second suspension comprising the second carrier liquid composition and the powder to the plume of the thermal spray device; and forming a second portion of the coating comprising the powder on the substrate from the second suspension.

A method for forming a hydrophobic coating on a substrate by a thermal spray deposition process is described. The method may comprise feeding a thermal spray apparatus with a coating precursor consisting of particles having an initial particle morphology, and heating the particles with the thermal spray apparatus to cause the particle to at least partially melt. The method may further comprise accelerating the particles towards the substrate, and forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the particles is retained.

A method for forming a hydrophobic coating on a substrate by a thermal spray deposition process is described. The method may comprise feeding a thermal spray apparatus with a coating precursor consisting of particles having an initial particle morphology, and heating the particles with the thermal spray apparatus to cause the particle to at least partially melt. The method may further comprise accelerating the particles towards the substrate, and forming the hydrophobic coating on the substrate by allowing the particles to impact the substrate in a partially melted state in which a fraction of the initial particle morphology of at least some of the particles is retained.

The invention relates to a method for hydrophilicizing a semi-finished element, in particular an electrode element, a bipolar element and/or a heat exchanger element, made of a plastic material or plastic composite material containing at least one thermoplastic and/or at least one thermosetting plastic. In order that the wettability of the component surface for aqueous media can be increased with smaller structure changes, with lower costs and with less effort, provision is made for the hydrophilicizing to be caused at least partially by applying carbon particles at least in sections on at least one surface of the semi-finished element and the carbon particles to be applied by rubbing, pressurised gas jet and/or by electrostatics at least in sections on the at least one surface in such manner that the carbon particles remain adhered to the surface.

The invention relates to a method for hydrophilicizing a semi-finished element, in particular an electrode element, a bipolar element and/or a heat exchanger element, made of a plastic material or plastic composite material containing at least one thermoplastic and/or at least one thermosetting plastic. In order that the wettability of the component surface for aqueous media can be increased with smaller structure changes, with lower costs and with less effort, provision is made for the hydrophilicizing to be caused at least partially by applying carbon particles at least in sections on at least one surface of the semi-finished element and the carbon particles to be applied by rubbing, pressurised gas jet and/or by electrostatics at least in sections on the at least one surface in such manner that the carbon particles remain adhered to the surface.