Provided is a forming method of a metal layer suitable for a 3D printing process. The method includes the steps of providing a plurality of metal particles on a substrate; applying an oxide-removing agent to the metal particles to remove metal oxides on the metal particles; at a first temperature, performing a first heat treatment on the metal particles for which the metal oxides are removed to form a near shape; and at a second temperature, performing a second heat treatment on the near shape to form a sintered body. The first temperature is lower than the second temperature.

Provided is a forming method of a metal layer suitable for a 3D printing process. The method includes the steps of providing a plurality of metal particles on a substrate; applying an oxide-removing agent to the metal particles to remove metal oxides on the metal particles; at a first temperature, performing a first heat treatment on the metal particles for which the metal oxides are removed to form a near shape; and at a second temperature, performing a second heat treatment on the near shape to form a sintered body. The first temperature is lower than the second temperature.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area; and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torquing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

The invention relates to an electrolyte for electropolishing metal surfaces, said electrolyte comprising methanesulphonic acid and additionally at least one phosphonic acid, as well as to an electropolishing method for same.

The invention relates to an electrolyte for electropolishing metal surfaces, said electrolyte comprising methanesulphonic acid and additionally at least one phosphonic acid, as well as to an electropolishing method for same.

A part includes a three-dimensional porous metallic workpiece printed via an additive manufacturing process and subsequently subjected to a diffusion-based process to convert at least a portion of the porous metallic workpiece to a ceramic workpiece or an intermetallic workpiece.

A part includes a three-dimensional porous metallic workpiece printed via an additive manufacturing process and subsequently subjected to a diffusion-based process to convert at least a portion of the porous metallic workpiece to a ceramic workpiece or an intermetallic workpiece.

A method for manufacturing iron-based metallurgical parts, the method comprising: mixing graphite powder; pressing; presintering; oxidizing the presintered metallurgical part to form an oxide layer having a thickness of 1 m to 50 m on its surface to form an oxidized presintered metallurgical part; sintering; machining; carburizing; quenching and tempering. An oxide layer is formed on the surface of a part by oxidization, oxygen in the oxide layer is chemically reacted with the carbon in the surface layer of the product during the sintering, and the resulting product enters a sintering atmosphere in the form of gas to form a decarburized layer having a certain thickness on the surface of the part, so that the decarburization is realized.

A method for manufacturing iron-based metallurgical parts, the method comprising: mixing graphite powder; pressing; presintering; oxidizing the presintered metallurgical part to form an oxide layer having a thickness of 1 m to 50 m on its surface to form an oxidized presintered metallurgical part; sintering; machining; carburizing; quenching and tempering. An oxide layer is formed on the surface of a part by oxidization, oxygen in the oxide layer is chemically reacted with the carbon in the surface layer of the product during the sintering, and the resulting product enters a sintering atmosphere in the form of gas to form a decarburized layer having a certain thickness on the surface of the part, so that the decarburization is realized.

The present disclosure provides a sintered neodymium-iron-boron permanent magnet, a preparation method and use thereof. The permanent magnet described herein comprises a grain and a grain boundary phase. The grain boundary phase is located on an epitaxial layer of the grain. The grain boundary phase comprises at least an RH. The grain comprises at least Nd.sub.2Fe.sub.14B. In the grain boundary phase within a depth of 100 ?m from the surface to the center of the sintered neodymium-iron-boron permanent magnet, the area of the grain boundary phase with an RH content of more than 6 wt % accounts for 50% or more of the total area of the grain boundary phase. The present disclosure adopts an RH and an RL as the diffusion source for composite diffusion, significantly improving the coercivity of the permanent magnet and the utilization rate of the RH in the diffusion source.