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 the oxide formation associated with laser machining.

An external element made from a first material for a wearable object, the first material being an insulating ceramic, wherein a surface of the external element is at least partially treated to include at least one conversion with an electrical conductivity.

A ceramic sputtering target, wherein when a cross-sectional structure of a sputtering surface is observed with an electron microscope, an amount of microcracks defined below is 50 μm/mm or less, and after performing a peel test on the sputtering surface, an area ratio of peeled particles confirmed by observing the cross-sectional structure with an electron microscope is 1.0% or less.

Amount of microcracks=frequency of microcracks×average depth of microcracks

A method of selectively removing at least part of a first phase from a surface of a nanocomposite includes at least a first phase and a second phase, each phase having a respective threshold fluence under a given number of applied laser pulses for removal of the phase by laser ablation. The threshold fluence of the first phase is less than the threshold fluence of the second phase. The method includes irradiating the surface of the nanocomposite with a laser beam having a laser beam diameter, a laser pulse duration, and a laser pulse energy during the irradiation. The laser fluence during the irradiation is less than the threshold fluence of the second phase and greater than the threshold fluence of the first phase. The laser beam diameter is greater than an average grain size of the first phase at the surface of the nanocomposite.

A method of redefining an opening in a composite component comprises filling the opening with a filling material, where the opening is defined in a body of the composite component and opens onto a surface defined by the composite component, and redefining the opening such that the opening extends into the body. Some methods comprise removing an existing coating from the surface of the composite component prior to filling the opening with the filling material and applying a new coating to the surface prior to redefining the opening such that the opening extends through the new coating and into the body. An exemplary composite component comprises a body, a surface with a coating thereon, an original opening defined through the body and filled with a filling material, and a new opening defined through the coating into the body, which may be defined at a new location from the original opening.

A method of redefining an opening in a composite component comprises filling the opening with a filling material, where the opening is defined in a body of the composite component and opens onto a surface defined by the composite component, and redefining the opening such that the opening extends into the body. Some methods comprise removing an existing coating from the surface of the composite component prior to filling the opening with the filling material and applying a new coating to the surface prior to redefining the opening such that the opening extends through the new coating and into the body. An exemplary composite component comprises a body, a surface with a coating thereon, an original opening defined through the body and filled with a filling material, and a new opening defined through the coating into the body, which may be defined at a new location from the original opening.

A method for machining a ceramic matrix composite (CMC), the method enhancing a machining speed for the ceramic matrix composite (CMC), includes: a step of scanning an irradiated portion of a surface of a machining target material by a laser head to irradiate the irradiated portion with laser light from the laser head, and forming a deteriorated layer on the irradiated portion of the surface of the machining target material; and a step of sequentially removing the deteriorated layer by an end mill, the deteriorated layer being formed on the irradiated portion, wherein the deteriorated layer is formed by heating the irradiated portion up to a predetermined temperature by irradiation of continuous oscillation laser light, and by forming a crack by irradiation of pulsed oscillation laser light.

A method for machining a ceramic matrix composite (CMC), the method enhancing a machining speed for the ceramic matrix composite (CMC), includes: a step of scanning an irradiated portion of a surface of a machining target material by a laser head to irradiate the irradiated portion with laser light from the laser head, and forming a deteriorated layer on the irradiated portion of the surface of the machining target material; and a step of sequentially removing the deteriorated layer by an end mill, the deteriorated layer being formed on the irradiated portion, wherein the deteriorated layer is formed by heating the irradiated portion up to a predetermined temperature by irradiation of continuous oscillation laser light, and by forming a crack by irradiation of pulsed oscillation laser light.

Aqueous compositions may be used preparing special concretes like aerated concrete or lightweight concrete. Such an aqueous composition for preparing such concretes, may combine water, a hydraulic binder, and an aggregate that is ground in the presence of a particular anionic polymer. The ground aggregate is selected from slag, fly ash, sand, and combinations thereof.

An object of the present invention is to provide a novel technique capable of suppressing the occurrence of cracks in an AlN layer.

The present invention is a method for manufacturing an AlN substrate, the method including: an embrittlement processing step S10 of reducing strength of a SiC underlying substrate 10; and a crystal growth step S20 of forming an AlN layer 20 on the SiC underlying substrate 10. In addition, the present invention is a method for suppressing the occurrence of cracks in the AlN layer 20, the method including the embrittlement processing step S10 of reducing the strength of the SiC underlying substrate 10 before forming the AlN layer 20 on the SiC underlying substrate 10.