Alloys comprised of a refined microstructure, ultrafine or nano scaled, that when reacted with water or any liquid containing water will spontaneously and rapidly produce hydrogen at ambient or elevated temperature are described. These metals, termed here as aluminum based nanogalvanic alloys will have applications that include but are not limited to energy generation on demand. The alloys may be composed of primarily aluminum and other metals e.g. tin bismuth, indium, gallium, lead, etc. and/or carbon, and mixtures and alloys thereof. The alloys may be processed by ball milling for the purpose of synthesizing powder feed stocks, in which each powder particle will have the above mentioned characteristics. These powders can be used in their inherent form or consolidated using commercially available techniques for the purpose of manufacturing useful functional components.

High ultraviolet transmittance and high blackness can be obtained, and also has high insulating property.

A zirconium nitride powder of the present invention has a volume resistivity of 10.sup.7 Ω.Math.cm or more in the state of the pressurized powder body hardened at a pressure of 5 MPa, and a particle size distribution D.sub.90 of 10 μm or less when ultrasonically dispersed for 5 minutes in a state of being diluted with water or an alcohol having a carbon number of which is in a range of 2 to 5. Also, the zirconium nitride powder is dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. Further, the zirconium nitride powder is dispersed in a dispersing medium as a black pigment and further a resin is mixed to prepare a black composition.

The method of producing a solid spherical powder according to the present disclosure includes: a step A of preparing a first powder raw material containing agglomerated particles and/or solidified particles having a particle diameter of 1 μm to 1,000 μm and introducing the first powder raw material into a plasma flame to produce a hollow spherical powder having a surface layer shell having a thickness of 1 μm to 50 μm; a step B of subjecting the hollow spherical powder to pulverization treatment to pulverize a hollow shape of the hollow spherical powder, thus obtaining a second powder raw material which is solid; and a step C of introducing the second powder raw material into a plasma flame, melting and solidifying the second powder raw material to obtain the solid spherical powder.

The method of producing a solid spherical powder according to the present disclosure includes: a step A of preparing a first powder raw material containing agglomerated particles and/or solidified particles having a particle diameter of 1 μm to 1,000 μm and introducing the first powder raw material into a plasma flame to produce a hollow spherical powder having a surface layer shell having a thickness of 1 μm to 50 μm; a step B of subjecting the hollow spherical powder to pulverization treatment to pulverize a hollow shape of the hollow spherical powder, thus obtaining a second powder raw material which is solid; and a step C of introducing the second powder raw material into a plasma flame, melting and solidifying the second powder raw material to obtain the solid spherical powder.

Provided is a potassium titanate powder that can avoid safety and health concerns and concurrently, during use in a friction material, can give excellent frictional properties. A potassium titanate powder is a powder formed of bar-like potassium titanate particles having an average length of 30 μm or more, an average breadth of 10 m or more, and an average aspect ratio of 1.5 or more, wherein the bar-like potassium titanate particles are represented by a composition formula K.sub.2Ti.sub.nO.sub.2n+1 (where n=5.5 to 6.5).

To provide a method for efficiently producing metal microparticles having a particle diameter of 1 μm to 10 μm, and a device for producing the same. A metal microparticle production method is used, which includes a particle generating step of generating primary particles by irradiating a metal lump in a solvent in a first tank with an ultrasonic wave, and a particle splitting step of irradiating the primary particles with an ultrasonic wave in a solvent in a second tank and splitting the primary particles to produce secondary particles. Further, a metal microparticle production device is used, which includes: a first tank that has a solvent and a metal lump; a first heating unit that heats the solvent in the first tank; a first ultrasonic vibrator that is disposed in the first tank and irradiates the metal lump with an ultrasonic wave to generate primary particles; a second tank that has the solvent and the primary particles; and a second ultrasonic vibrator that irradiates the primary particles with an ultrasonic wave to split the primary particles.

Provided is a potassium titanate powder that can avoid safety and health concerns and concurrently, during use in a friction material, can give excellent frictional properties. A potassium titanate powder is a powder formed of bar-like potassium titanate particles having an average length of 30 μm or more, an average breadth of 10 μm or more, and an average aspect ratio of 1.5 or more, wherein the bar-like potassium titanate particles are represented by a composition formula K.sub.2Ti.sub.nO.sub.2n+1 (where n=5.5 to 6.5).

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A Mn-based alloy according to the present invention is a MnAl alloy having metamagnetism. The metamagnetism refers to a property in which magnetism undergoes transition from paramagnetism or antiferromagnetism to ferromagnetism by a magnetic field. In the MnAl alloy, an antiferromagnetic state is adequately stable, so that by imparting AFM-FM transition type metamagnetism (the type of metamagnetism undergoing transition from antiferromagnetism to ferromagnetism), it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of −100° C. to 200° C.

Provided is a potassium titanate powder that can avoid safety and health concerns and concurrently, during use in a friction material, can give excellent frictional properties. A potassium titanate powder is a powder formed of bar-like potassium titanate particles having an average length of 30 μm or more, an average breadth of 10 μm or more, and an average aspect ratio of 1.5 or more, wherein the bar-like potassium titanate particles are represented by a composition formula K.sub.2Ti.sub.nO.sub.2n+1 (where n=5.5 to 6.5).

To provide an R-T-B based sintered magnet including R: 27.5 to 34.0% by mass, RH: 2 to 10% by mass, B: 0.89 to 0.95% by mass, Ti: 0.1 to 0.2% by mass, Ga: 0.3 to 0.7% by mass, Cu: 0.07 to 0.50% by mass, Al: 0.05 to 0.50% by mass, M (M is Nb and/or Zr): 0 to 0.3% by mass, balance T, and inevitable impurities, the following inequality expressions (1), (2), and (3) being satisfied:
[T]72.3([B]0.45[Ti])>0(1)
([T]72.3([B]0.45[Ti]))/55.85<13[Ga]/69.72(2)
[Ga][Cu](3).