A method for three-dimensional printing includes printing a three-dimensional part formed form a first material, the first material including induction sensitive particles and applying magnetic induction to the three-dimensional part during or after printing to heat the induction sensitive particles and melt the first material, allowing reflow thereof. The method also includes printing a support structure. The support structure may also include induction sensitive particles.

In a method for producing a material sheet, in particular a metallic material sheet, a green body containing solid-state particles is sintered at a sintering temperature by heating the green body during sintering at least partly using microwave energy in accordance with a defined temperature profile having a heating phase and an essentially isothermal hold phase. A temperature of the green body is ascertained contactlessly with a sensor, and a supply of heat energy is controlled as a function of the temperature of the green body. During the heating phase an average microwave power is supplied and during the hold phase another average microwave power is supplied which is less than the one average microwave power.

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.

An additive manufacturing apparatus including a build chamber containing a support for supporting a material bed, a layering device for forming layers of the material bed, a laser or electron beam source for generating a laser or electron beam, a device for steering the laser or electron beam to solidify selected areas of each layer to form a part and a microwave or radio wave source controllable to generate a microwave or radio wave field to differentially heat the material bed based upon the selected areas.

An additive manufacturing apparatus including a build chamber containing a support for supporting a material bed, a layering device for forming layers of the material bed, a laser or electron beam source for generating a laser or electron beam, a device for steering the laser or electron beam to solidify selected areas of each layer to form a part and a microwave or radio wave source controllable to generate a microwave or radio wave field to differentially heat the material bed based upon the selected areas.

Provided herein are systems, apparatuses, and methods for generating a three-dimensional (3D) object using an energy beam array. Also provided herein are systems, apparatuses and methods for generating a 3D object with small-scaffold features, as well as systems, apparatuses and methods for generating a 3D object using roll-to-roll. The roll-to-roll apparatus may include a moving platform of the 3D object. The 3D object can be formed by an additive manufacturing process from a material such as powder.

Provided is a simple, fast, scalable, and environmentally benign method of producing a graphene-reinforced inorganic matrix composite directly from a graphitic material, the method comprising: (a) mixing multiple particles of a graphitic material and multiple particles of an inorganic solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of solid inorganic carrier material particles to produce graphene coated or graphene-embedded inorganic particles inside the impacting chamber; and (c) forming graphene-coated or graphene-embedded inorganic particles into the graphene-reinforced inorganic matrix composite. Also provided is a mass of the graphene-coated or graphene-embedded inorganic particles produced by this method.

Provided is a simple, fast, scalable, and environmentally benign method of producing a graphene-reinforced inorganic matrix composite directly from a graphitic material, the method comprising: (a) mixing multiple particles of a graphitic material and multiple particles of an inorganic solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of solid inorganic carrier material particles to produce graphene coated or graphene-embedded inorganic particles inside the impacting chamber; and (c) forming graphene-coated or graphene-embedded inorganic particles into the graphene-reinforced inorganic matrix composite. Also provided is a mass of the graphene-coated or graphene-embedded inorganic particles produced by this method.

In at least one embodiment, a hybrid permanent magnet is disclosed. The magnet may include a plurality of anisotropic regions of a Nd—Fe—B alloy and a plurality of anisotropic regions of a MnBi alloy. The regions of Nd—Fe—B alloy and MnBi alloy may be substantially homogeneously mixed within the hybrid magnet. The regions of Nd—Fe—B and MnBi may have the same or a similar size. The magnet may be formed by homogeneously mixing anisotropic powders of MnBi and Nd—Fe—B, aligning the powder mixture in a magnetic field, and consolidating the powder mixture to form an anisotropic hybrid magnet. The hybrid magnet may have improved coercivity at elevated temperatures, while still maintaining high magnetization.