A method for manufacturing an R-T-B based sintered magnet according the present disclosure comprises: a step for preparing a coarse ground powder which is made from an alloy for R-T-B based sintered magnets and which has an average particle size of 10-500 μm; a step for obtaining a fine powder having an average particle size of 2.0-4.5 μm, by feeding the coarse ground powder to a jet mill device that has a grinding chamber filled with inert gas and grinding the coarse ground powder; and a step for producing a sintered body of the fine powder, wherein the inert gas has been humidified, and the oxygen content of the R-T-B based sintered magnet is 1000-3500 ppm by mass.

A method for manufacturing an R-T-B based sintered magnet according the present disclosure comprises: a step for preparing a coarse ground powder which is made from an alloy for R-T-B based sintered magnets and which has an average particle size of 10-500 μm; a step for obtaining a fine powder having an average particle size of 2.0-4.5 μm, by feeding the coarse ground powder to a jet mill device that has a grinding chamber filled with inert gas and grinding the coarse ground powder; and a step for producing a sintered body of the fine powder, wherein the inert gas has been humidified, and the oxygen content of the R-T-B based sintered magnet is 1000-3500 ppm by mass.

A cemented carbide having an eta phase and a Ni—Al binder is provided. The binder includes intermetallic γ′-Ni.sub.3Al-precipitates embedded in a substitutional solid solution matrix including Al and Ni. Further, the cemented carbide has a surface zone free from eta phase. A method of making a cutting tool is also provided.

A cemented carbide having an eta phase and a Ni—Al binder is provided. The binder includes intermetallic γ′-Ni.sub.3Al-precipitates embedded in a substitutional solid solution matrix including Al and Ni. Further, the cemented carbide has a surface zone free from eta phase. A method of making a cutting tool is also provided.

A method of and system for surface finishing an additive manufactured part. A part having a surface roughness with macroasperities is placed in a chamber with an electrolyte and an electrode. A pulse/pulse reverse power supply is connected to the part rendering it anodic and connected to the electrode rendering it cathodic. The power supply is operated to decrease the surface roughness of the part by applying a first series of waveforms including at least two waveforms where a diffusion layer is maintained at a thickness to produce a macroprofile regime relative to the macroasperities, the first series of waveforms having anodic voltages applied for anodic time periods before cathodic voltages applied for cathodic time periods to effect part surface smoothing to a first surface roughness with minimal material removal and applying a final waveform where the diffusion layer represents a microprofile regime, the final waveform having a final anodic voltage applied for a final anodic time period before a final cathodic voltage applied for a final cathodic time period to effect part surface smoothing to a final surface roughness with minimal material removal.

A method of and system for surface finishing an additive manufactured part. A part having a surface roughness with macroasperities is placed in a chamber with an electrolyte and an electrode. A pulse/pulse reverse power supply is connected to the part rendering it anodic and connected to the electrode rendering it cathodic. The power supply is operated to decrease the surface roughness of the part by applying a first series of waveforms including at least two waveforms where a diffusion layer is maintained at a thickness to produce a macroprofile regime relative to the macroasperities, the first series of waveforms having anodic voltages applied for anodic time periods before cathodic voltages applied for cathodic time periods to effect part surface smoothing to a first surface roughness with minimal material removal and applying a final waveform where the diffusion layer represents a microprofile regime, the final waveform having a final anodic voltage applied for a final anodic time period before a final cathodic voltage applied for a final cathodic time period to effect part surface smoothing to a final surface roughness with minimal material removal.

A polishing method for an inner wall of a hollow metal part, including: firstly, placing a coaxial cathode in an inner hole of a metal part when a metal part model is designed, and printing the metal part model and the coaxial cathode together; then, sealing two ends of an inner hole cavity of the metal part by using a light curing part, fixing the coaxial cathode, filling the cavity with a polishing solution, and performing polishing treatment by using an electrochemical polishing method; and finally, reversing an electrode to break the coaxial cathode and take out the broken coaxial cathode to obtain a polished metal part. The polishing of a complex-shaped inner hole of a 3D-printed metal part is realized, the defect that an inner hole of a 3D-printed metal part with a complex-shaped hollow part cannot be polished by using a traditional machining method is overcome, the problem that an inner wall of a metal part polished by using an electrochemical method is non-uniform is solved, the surface quality of the inner hole of the 3D-printed metal part with the complex-shaped hollow part is improved, and the application prospect and postprocessing technology of the 3D-printed metal part are expanded.

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 fabrication method involving the use of additive material fabrication methods to create a shell representative of a desired part, the additive material shell being used in one or more molding fabrication methods in which a second material is provided into a cavity of the shell.