To provide a sintered material having excellent oxidation resistance, as well as excellent abrasion resistance and chipping resistance. A sintered material containing a first compound formed of Ti, Al, Si, O, and N is provided.

A hard composite composition may comprise a binder and a polymodal blend of matrix powder. The polymodal blend of matrix powder may have at least one first local maxima at a particle size of about 0.5 nm to about 30 m, at least one second local maxima at a particle size of about 200 m to about 10 mm, and at least one local minima between a particle size of about 30 m to about 200 m that has a value that is less than the first local maxima.

Composites having the composition of at least one principal strengthening phase compound and one cemented phase of principal refractory metal are disclosed. The components of the strengthening phase compound can be a boride or a mixture of a boride and one or more than one carbide. In addition, the composites are obtained by smelting the principal strengthening phase compound and the cemented phase principal refractory metal in a non-equal molar ratio.

A method of making abrasive particles includes exposing ceramic particles to an organosilane-derived plasma formed from components comprising an organosilane and oxygen to form plasma-modified ceramic particles; and contacting a coupling agent with the second plasma-treated ceramic particle to provide the abrasive particle. Abrasive particles preparable by the method and abrasive particles containing them are also disclosed.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

A sintered polycrystalline body and a method of forming the sintered polycrystalline body are disclosed. The sintered polycrystalline body comprises a plurality of particles cubic boron nitride dispersed in a matrix. The matrix includes materials selected from compounds of any of titanium and aluminium. The polycrystalline body further comprises 0.1 to 5.0 volume % of lubricating chalcogenide particles dispersed in the matrix. The chalcogenide particles have a coefficient of friction of less than 0.1 with respect to a workpiece material. Preferably sulfide particles are used as lubricant. Preferably 30-70 vol.-% cBN is contained. Sintering takes place at 1100-1600 C. and 4-8 GPa.

A method of producing the composite reinforcing material includes a step of kneading at least a graphite-based carbon material and a reinforcing material into a base material. The graphite-based carbon material is characterized by having a rhombohedral graphite layer (3R) and a hexagonal graphite layer (2H), wherein a Rate (3R) of the rhombohedral graphite layer (3R) and the hexagonal graphite layer (2H), based on an X-ray diffraction method, which is defined by following Equation 1 is 31% or more:

Rate(3R)=P3/(P3+P4)100 (Equation 1)

wherein P3 is a peak intensity of a (101) plane of the rhombohedral graphite layer (3R) based on the X-ray diffraction method, and P4 is a peak intensity of a (101) plane of the hexagonal graphite layer (2H) based on the X-ray diffraction method.

A stiffness controlled abradeable seal system for a gas turbine engine includes a cantilevered arm that supports one of a rotating seal surface and a static seal surface, a stiffness of the cantilevered arm controlled to achieve a desired operational temperature at a seal interface.