A porous ceramic honeycomb body (10) including intersecting walls that form channels (22) extending axially from a first end face to a second end face and layered plugs (62) comprised of a first layer (64) disposed on channel walls and a second layer (66) disposed inward toward an axial center of each respective channel on the first layer. The plugs seal at least one of a first portion of the channels at the first end face and a second portion of channels at the second end face of the porous ceramic honeycomb body.

Provided is a hearth roll for supporting and conveying a steel sheet in a continuous annealing furnace, wherein all of a shaft portion and a roil main body are made from one or more ceramic materials, preferably constituted with concentric ceramic layers of different ceramic materials centering on the rotation shaft of the roll. The hearth roll has not only an excellent pickup resistance but also a long roll life free from maintenance for long periods. Also provided is a continuous annealing facility using the hearth roll in at least one of a heating zone, a soaking zone and a cooling zone.

A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm; ° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

A mullite-containing sintered body according to the present invention contains mullite and at least one selected from the group consisting of silicon nitride, silicon oxynitride, and sialon. It is preferable that the mullite-containing sintered body have a thermal expansion coefficient of less than 4.3 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1.5 μm or less.

A three-dimensional (3D) printing composition includes ceramic filaments comprising an additive having an aspect ratio of at least 2:1. 3D printed ceramic articles include the ceramic filaments.

A sintered body of the present invention is a sintered body including a first material and cubic boron nitride. The first material is partially-stabilized ZrO.sub.2 including 5 to 90 volume % of Al.sub.2O.sub.3 dispersed in crystal grain boundaries or crystal grains of partially-stabilized ZrO.sub.2.

A method for forming in situ a boron nitride reaction product locally on a reinforcement phase of a ceramic matrix composite material includes the steps of providing a ceramic matrix composite material having a fiber reinforcement material; and forming in situ a layer of boron nitride on the fiber reinforcement material.

A method of manufacturing an article includes providing a component for an etch reactor. Ion beam sputtering with ion assisted deposition (IBS-IAD) is then performed to deposit a protective layer on at least one surface of the component, wherein the protective layer is a plasma resistant film having a thickness of less than 1000 μm.

A self-lubricating flexible carbon composite seal includes an annular body formed from a flexible carbon composite.

A hard material which, when used as a material of a sintered material, makes it possible to obtain a sintered material with excellent abrasion resistance, a sintered material, a cutting tool including the sintered material, a method for manufacturing the hard material and a method for manufacturing the sintered material are provided. The hard material contains aluminum, nitrogen, and at least one element selected from the group consisting of titanium, chromium, and silicon, and has a cubic rock salt structure.