Disclosed is a method for making a ceramic matrix composite. The method includes infiltrating an initial ceramic matrix composite with a molten silicon infiltration material to form a silicon infiltrated composite; cooling the silicon infiltrated composite; heating a first portion of the cooled silicon infiltrated composite to a temperature in excess of the melt temperature of the silicon infiltration material in the presence of a carbon source; heating a second portion of the cooled silicon infiltrated composite to a temperature in excess of the melt temperature of the silicon infiltration material in the presence of a carbon source after heating the first portion; and cooling the heated portions to form a final ceramic matrix composite, wherein the first portion and second portion of the cooled silicon infiltrated composite are adjacent or overlap.

The present disclosure provides a transparent alumina-based plate, and a hot-pressing method to make the transparent alumina-based plate from platelet alumina. Alumina powder with a platelet morphology was hot-pressed to transparency with pre-load pressures of about 0-8 MPa, maximum temperatures of about 1750-1825° C., maximum pressures of about 2.5-80 MPa, and isothermal hold times of 1-7 hours. A novel alumina-based plate has been prepared, wherein the plate has a thickness of 2-5 mm, an in-line transmission of at least 60-75% for a light with a wavelength range of 645-2500 nm, an in-line transmission variance of <15% over the wavelength range of 645-2500 nm, and a relative density of 99.00-99.95%.

A Cr:YAG sintered body including Al, Y, Cr, Ca, Mg, Si, and O, and component contents in the sintered body satisfying conditional expressions of 1) to 3) below, provided in the Conditional expression, each chemical symbol represents a component content (atppm).
|(Y+Ca)/(Al+Cr+Si+Mg)−0.6|<0.001;  1)
0≤(Ca+Mg)−(Cr+Si)≤50 atppm; and  2)
50≤Si≤500 atppm  3) The embodiment of the present invention is to provide a Cr:YAG sintered body which exhibits high transparency and has a high Cr.sup.4+ conversion ratio, and its production method.

A fiber reinforced composite component may include interleaved fiber layers and ceramic particle layers coated with matrix material. The fiber reinforced composite component may be fabricated by forming a fibrous preform, needling the fibrous preform to form a plurality of z-direction fibers, and densifying the fibrous preform. The fibrous preform may be fabricated by forming a first ceramic particle layer over a first fiber layer, disposing a second fiber layer over the first ceramic particle layer, forming a second ceramic particle layer over the second fiber layer, and disposing a third fiber layer over the second ceramic particle layer.

A cutting tool including a substrate and a coating film disposed on the substrate, wherein the cutting tool includes: a rake face; a flank face contiguous to the rake face; and a cutting edge region composed of a boundary part between the rake face and the flank face, wherein the coating film includes a TiSiCN layer, the TiSiCN layer has: a first TiSiCN layer positioned in the rake face; and a second TiSiCN layer positioned in the cutting edge region, the first TiSiCN layer has a composition of Ti.sub.(1-Xr)Si.sub.XrCN, the second TiSiCN layer has a composition of Ti.sub.(1-Xe)Si.sub.XeCN, and the Xr and the Xe each represent 0.010 or more and 0.100 or less, and satisfy a relationship of Xe-Xr≥0.003.

A ceramic matrix composite article includes a melt infiltration ceramic matrix composite substrate comprising a ceramic fiber reinforcement material in a ceramic matrix material having a first free silicon proportion, and a melt infiltration ceramic matrix composite outer layer comprising a ceramic fiber reinforcement material in a ceramic matrix material having a second free silicon proportion disposed on an outer surface of at least a portion of the substrate, or a polymer impregnation and pyrolysis ceramic matrix composite outer layer comprising a ceramic fiber reinforcement material in a ceramic matrix material having a second free silicon proportion disposed on an outer surface of at least a portion of the substrate. The second free silicon proportion is less than the first free silicon proportion.

A silicon carbide-graphite composite is described, including (i) interior bulk graphite material and (ii) exterior silicon carbide matrix material, wherein the interior bulk graphite material and exterior silicon carbide matrix material inter-penetrate one another at an interfacial region therebetween, and wherein graphite is present in inclusions in the exterior silicon carbide matrix material. Such material may be formed by contacting a precursor graphite article with silicon monoxide (SiO) gas under chemical reaction conditions that are effective to convert an exterior portion of the precursor graphite article to a silicon carbide matrix material in which graphite is present in inclusions therein, and wherein the silicon carbide matrix material and interior bulk graphite material interpenetrate one another at an interfacial region therebetween. Such silicon carbide-graphite composite is usefully employed in applications such as implant hard masks in manufacturing solar cells or other optical, optoelectronic, photonic, semiconductor and microelectronic products, as well as in ion implantation system materials, components, and assemblies, such as beam line assemblies, beam steering lenses, ionization chamber liners, beam stops, and ion source chambers.

A method of manufacture for a carbon/carbon part including a method to remove contamination from an intermediate product of the carbon/carbon part and furnace utilizing a gaseous reducing agent hydrogen gas to reduce the contaminates, thereby causing the contaminates to transition to a gaseous state at relatively lower temperatures. A method to remove contamination from an intermediate product of the carbon/carbon part and furnace utilizing hydrogen gas to reduce the contaminates, thereby causing the contaminates to transition to a gaseous state at relatively lower temperatures.

Methods for preparing ceramic matrix composites using melt infiltration and chemical vapor infiltration are provided as well as the resulting ceramic matrix composites. The methods and products include the incorporation of sacrificial fibers to provide improved infiltration of the fluid infiltrant. The sacrificial fibers are removed, such as decomposed during pyrolysis, resulting in the formation of regular and elongate channels throughout the ceramic matrix composite. Infiltration of the fluid infiltrant can then take place using the elongate channels resulting in improved density and an improved ceramic matrix composite product.

Provided are a ceramic complex having high light emission intensity and a method for producing the same. Proposed is a ceramic complex, including a rare earth aluminate fluorescent material having a composition represented by the following formula (I) and an aluminum oxide, wherein the content of the aluminum oxide is 70% by mass or more, the content of Na is 7 ppm by mass or less, the content of Si is 5 ppm by mass or less, the content of Fe is 3 ppm by mass or less, and the content of Ga is 5 pm by mass or less, relative to the total amount of the rare earth aluminate fluorescent material having a composition represented by the following formula (I) and the aluminum oxide.
(Ln.sub.1-aCe.sub.a).sub.3Al.sub.5O.sub.12   (I) wherein Ln represents at least one element selected from the group consisting of Y, Gd, Lu, and Tb; and a satisfies 0<a≤0.022.