The present disclosure relates to a wear part made in a foundry. The wear part has a reinforced portion comprising a ferrous alloy reinforced with metal carbides, nitrides, borides, or intermetallic alloys. The reinforced portion includes inserts of metal carbides, nitrides, metal, or intermetallic compounds manufactured beforehand with a defined geometry and inserted into an infiltrable structure of agglomerated grains including the reagents needed for the formation of metal or intermetallic carbides, nitrides, borides according to an in situ self-propagating thermal reaction initiated during the casting of the ferrous alloy.

A cBN sintered material comprising cBN particles and a binder phase, in which the binder phase contains AlN and AlB.sub.2, a content proportion of cBN particles is 70 to 97 vol %, cBN sintered material has a volume resistivity up to 5×10.sup.−3 Ωcm, a rate of a peak intensity derived from Al with respect to a peak intensity derived from cBN particles is less than 1.0%, cBN particles include fine particles and coarse particles, coarse particles optionally include ultra-coarse particles, with respect to the entire cBN particles, a content proportion α of fine particles is from 10 vol %, a content proportion β of coarse particles is from 30 vol %, a content proportion γ of ultra-coarse particles is 25 vol % or less, and a total of the content proportion α of fine particles and the content proportion β of coarse particles is 50 to 100 vol %.

Methods for producing components for use in high temperature systems that include reacting a fluid reactant and a porous preform that has a pore volume and contains a solid oxide reactant that defines a solid volume of the porous preform. The method includes infiltrating the fluid reactant into the porous preform to react with the solid oxide reactant to produce a oxide/metal composite component, during which a displacing metal replaces a displaceable species of the solid oxide reactant to produce at least one solid oxide reaction product that has a reaction product volume that at least partially fills the pore volume. The oxide/metal composite component includes at least one oxide phase and at least one metal phase. The component is exposed to temperatures greater than 500° C. and the at least one oxide phase and the at least one metal phase exhibit thermal expansion values within 50% of one another.

Methods for producing components for use in high temperature systems that include reacting a fluid reactant and a porous preform that has a pore volume and contains a solid oxide reactant that defines a solid volume of the porous preform. The method includes infiltrating the fluid reactant into the porous preform to react with the solid oxide reactant to produce a oxide/metal composite component, during which a displacing metal replaces a displaceable species of the solid oxide reactant to produce at least one solid oxide reaction product that has a reaction product volume that at least partially fills the pore volume. The oxide/metal composite component includes at least one oxide phase and at least one metal phase. The component is exposed to temperatures greater than 500° C. and the at least one oxide phase and the at least one metal phase exhibit thermal expansion values within 50% of one another.

A cBN sintered material comprising cBN particles and a binder phase, in which the binder phase contains AlN and AlB.sub.2, a content proportion of cBN particles is 70 to 97 vol %, cBN sintered material has a volume resistivity up to 5×10.sup.−3 Ωcm, a rate of a peak intensity derived from Al with respect to a peak intensity derived from cBN particles is less than 1.0%, cBN particles include fine particles and coarse particles, coarse particles optionally include ultra-coarse particles, with respect to the entire cBN particles, a content proportion α of fine particles is from 10 vol %, a content proportion β of coarse particles is from 30 vol %, a content proportion γ of ultra-coarse particles is 25 vol % or less, and a total of the content proportion α of fine particles and the content proportion β of coarse particles is 50 to 100 vol %.

The invention relates in a first aspect to a process for preparing a 3-dimensional body, in particular a vitreous or ceramic body, which comprises at least the following steps: a) providing an electrostatically stabilized suspension of particles; b) effecting a local destabilization of the suspension of particles by means of a localized electrical discharge between a charge injector and the suspension at a predetermined position and causing an aggregation and precipitation of the particles at said position; c) repeating step b) at different positions and causing the formation of larger aggregates until a final aggregate of particles representing a (porous) 3-dimensional body (green body) having predetermined dimensions has been formed; wherein the charge injector includes i) at least one discharge electrode which does not contact said suspension of particles or ii) a source of charged particles. A second aspect of the invention relates to a device, in particular for performing the above process, comprising at least the following components: —a vessel for receiving an electrostatically stabilized suspension of particles, —a charge injector, in particular including one or more electrodes or a source of high-energy charged particles, —means for moving the electrode and/or the vessel in the x, y and z directions, —a counter electrode arranged in the vessel for a contact with the suspension of particles, —one or more sensors for determining geometrical and physical parameters within said vessel. In one preferred embodiment, said device further comprises a means for directing a beam of gas-ionizing radiation, in particular a laser beam, to a predetermined position within the vessel.

Methods for producing oxide/metal composite components for use in high temperature systems, and components produced thereby. The methods use a fluid reactant and a porous preform that contains a solid oxide reactant. The fluid reactant contains yttrium as a displacing metal and the solid oxide reactant of the preform contains niobium oxide, of which niobium cations are displaceable species. The preform is infiltrated with the fluid reactant to react its yttrium with the niobium oxide of the solid oxide reactant and produce an yttria/niobium composite component, during which yttrium at least partially replaces the niobium cations of the solid oxide reactant to produce yttria and niobium metal, which together define a reaction product. The pore volume of the preform is at least partially filled by the reaction product, whose volume is greater than the volume lost by the solid oxide reactant as a result of reacting yttrium and niobium oxide.

Methods for producing oxide/metal composite components for use in high temperature systems, and components produced thereby. The methods use a fluid reactant and a porous preform that contains a solid oxide reactant. The fluid reactant contains yttrium as a displacing metal and the solid oxide reactant of the preform contains niobium oxide, of which niobium cations are displaceable species. The preform is infiltrated with the fluid reactant to react its yttrium with the niobium oxide of the solid oxide reactant and produce an yttria/niobium composite component, during which yttrium at least partially replaces the niobium cations of the solid oxide reactant to produce yttria and niobium metal, which together define a reaction product. The pore volume of the preform is at least partially filled by the reaction product, whose volume is greater than the volume lost by the solid oxide reactant as a result of reacting yttrium and niobium oxide.

A composite material is disclosed based on in situ produced alloys, especially iron based alloys, reinforced with tungsten carbide in the form of crystals and/or particles, that can be characterized by the fact that the microstructure of the composite material within the composite layer and/or the composite zone comprises faceted crystals and/or faceted particles tungsten carbide that provide uniform macroscopic and microscopic distribution, wherein the crystals and/or particles of tungsten carbide include irregular and/or round and/or oval nano and/or micro-areas filled with alloy based on metal. Compositions of powders used to produce the composite material and methods of its production as well as to cast working element made of such composite materials or using the method are disclosed.

A cast structural element of a pump, filter or compressor is disclosed with wear resistant layer comprising in situ produced composite material based on alloys, especially cast iron based alloys, reinforced with tungsten carbide in the form of crystals and/or particles, characterized by the microstructure of the composite material within the layer comprising faceted crystals and/or faceted particles tungsten carbide that provide uniform macroscopic and microscopic distribution, wherein the crystals and/or particles of tungsten carbide include irregular and/or round and/or oval nano and/or micro-areas filled with alloy based on metal. A method of producing the cast structural element in the form of a pump, filter or compressor is also disclosed.