A method of forming a super hard polycrystalline construction comprises forming a liquid suspension of nano-sized super hard particles and particles of super hard material having an average particle or grain size of 1 or more microns, dispersing the particles in the liquid suspension to form a substantially homogeneous suspension which is then dried and sintered to form a body of polycrystalline super hard material comprising a first and second fractions of super hard grains, the nano-sized particles forming the second fraction. The super hard grains in the first fraction are bonded along at least a portion of the peripheral surface(s) thereof to at least a portion of a plurality of nano-sized grains in the second fraction, the grains in the first fraction having a greater average grain size than that of the grains in the second fraction which is less than 999 nm, the average grain size of the first fraction being around 1 micron or more

The present disclosure discloses a preparation method of pressed Scandia-doped dispenser cathode using microwave sintering. Embodiments of the present disclosure include dissolving some nitrates and ammonium metatungstate with deionized water to prepare a homogeneous solution. Precursor powder with uniform size is obtained by spray drying, the precursor powder is decomposed, and two-step reduction may be proceeded to form doped tungsten powder with uniform element distribution. The cathode is prepared by one-time microwave sintering. One-time forming of cathode sintering is realized, and sintering shrinkage and sintering time are reduced significantly. The method has excellent repeatability, and the cathode has a homogeneous structure and excellent emission performance at 950° C.

The present disclosure discloses a preparation method of pressed Scandia-doped dispenser cathode using microwave sintering. Embodiments of the present disclosure include dissolving some nitrates and ammonium metatungstate with deionized water to prepare a homogeneous solution. Precursor powder with uniform size is obtained by spray drying, the precursor powder is decomposed, and two-step reduction may be proceeded to form doped tungsten powder with uniform element distribution. The cathode is prepared by one-time microwave sintering. One-time forming of cathode sintering is realized, and sintering shrinkage and sintering time are reduced significantly. The method has excellent repeatability, and the cathode has a homogeneous structure and excellent emission performance at 950° C.

A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

A method of producing a compacted article according to one embodiment may involve the steps of: Providing a copper/molybdenum disulfide composite powder including a substantially homogeneous dispersion of copper and molybdenum disulfide sub-particles that are fused together to form individual particles of the copper/molybdenum disulfide composite powder; and compressing the copper/molybdenum disulfide composite powder under sufficient pressure to cause the copper/molybdenum disulfide composite powder to behave as a nearly solid mass.

A method of producing a compacted article according to one embodiment may involve the steps of: Providing a copper/molybdenum disulfide composite powder including a substantially homogeneous dispersion of copper and molybdenum disulfide sub-particles that are fused together to form individual particles of the copper/molybdenum disulfide composite powder; and compressing the copper/molybdenum disulfide composite powder under sufficient pressure to cause the copper/molybdenum disulfide composite powder to behave as a nearly solid mass.

The present invention relates to a method of making a cemented carbide or a cermet body comprising the steps of first forming a powder blend comprising powders forming hard constituents and metal binder. The powder blend is then subjected to a mixing operation using a non-contact mixer wherein acoustic waves achieving resonance conditions to form a mixed powder blend and then subjecting said mixed powder blend to a pressing and sintering operation. The method makes it possible to maintain the grain size, the grain size distribution and the morphology of the WC grains.

An object is to provide an alloy composition that has a sufficient melting point for casting of an aluminum alloy, also has high hardness, and can suppress an occurrence of galling. The alloy composition of the present invention includes: a Mo—Cr-based dendritic structure 3; and a Ni—Al-based interdendritic structure 5 that fills a periphery of the Mo—Cr-based dendritic structure 3. The alloy composition of the present invention can adopt a chemical composition I in which when Mo+Cr+Ni+Al=100 at. % holds, Ni+Al=15 to 50 at. % and Mo+Cr=50 to 85 at. % hold; or a chemical composition II in which Ni+Al=40 to 70 at. % and Mo+Cr=30 to 60 at. % hold.

An object is to provide an alloy composition that has a sufficient melting point for casting of an aluminum alloy, also has high hardness, and can suppress an occurrence of galling. The alloy composition of the present invention includes: a Mo—Cr-based dendritic structure 3; and a Ni—Al-based interdendritic structure 5 that fills a periphery of the Mo—Cr-based dendritic structure 3. The alloy composition of the present invention can adopt a chemical composition I in which when Mo+Cr+Ni+Al=100 at. % holds, Ni+Al=15 to 50 at. % and Mo+Cr=50 to 85 at. % hold; or a chemical composition II in which Ni+Al=40 to 70 at. % and Mo+Cr=30 to 60 at. % hold.