An R-T-B-based permanent magnet which contains R that represents at least one rare earth element essentially including Tb or Dy, T that represents Fe or at least one iron-group element essentially including Fe and Co, and B that represents boron, and further contains Cu. The total content of R is 28.35 to 29.95% by mass, inclusive, the content of Cu is 0.05 to 0.40% by mass, inclusive, and the content of B is 0.93 to 1.00% by mass, inclusive. The distribution of the concentration of Tb or Dy decreases from the outside of the R-T-B-based permanent magnet toward the inside of the R-T-B-based permanent magnet.

A 3D-printed reflective optic providing very high specific stiffness through the utilization of a hollow shelled design, with closed back, filled with high-stiffness internal volumetric space-filling open-cell lattice structures. High-stiffness, structurally-integrated, sacrificial structures are also included for the purposes of reduction or elimination of tooling during post-processing operations.

A 3D-printed reflective optic providing very high specific stiffness through the utilization of a hollow shelled design, with closed back, filled with high-stiffness internal volumetric space-filling open-cell lattice structures. High-stiffness, structurally-integrated, sacrificial structures are also included for the purposes of reduction or elimination of tooling during post-processing operations.

A multilayered material system includes at least one of a liner sheet and a cellular core, and a multilayered composite joined to the at least one of a liner sheet and a cellular core. The multilayered composite includes hollow microspheres dispersed within a metallic matrix material.

A three-dimensional printing kit can include a particulate build material, a binding agent, and a supportive coating agent. The particulate build material can include from about 80 wt % to about 100 wt % metal particles based on the total weight of the particulate build material. The binding agent can include binder particles dispersed in a binder liquid vehicle. The supportive coating agent can include ceramic particles having a negative coefficient of thermal expansion, a gelling compound, and a supportive coating liquid vehicle.

A three-dimensional printing kit can include a particulate build material, a binding agent, and a supportive coating agent. The particulate build material can include from about 80 wt % to about 100 wt % metal particles based on the total weight of the particulate build material. The binding agent can include binder particles dispersed in a binder liquid vehicle. The supportive coating agent can include ceramic particles having a negative coefficient of thermal expansion, a gelling compound, and a supportive coating liquid vehicle.

Provided is a brazing filler material for bonding iron-based sintered member that includes a sintered compact containing Cu, Mn, and a remainder of Ni and unavoidable impurities, and an oxide film formed on a surface of the sintered compact. An oxygen concentration may account for not less than 0.1% by mass of a total amount of the brazing filler material. The oxide film may contain Mn.

Provided is a brazing filler material for bonding iron-based sintered member that includes a sintered compact containing Cu, Mn, and a remainder of Ni and unavoidable impurities, and an oxide film formed on a surface of the sintered compact. An oxygen concentration may account for not less than 0.1% by mass of a total amount of the brazing filler material. The oxide film may contain Mn.

Ground surface comprising a substrate (110) having a Young's modulus of between 100 and 1000 GPa, and in which the ground surface has, on a working surface (120), a Vickers hardness of between 1300 and 10 000 kgf/mm.sup.2, and/or a surface coating forming the working surface, in which the surface coating contains amorphous carbon and/or titanium nitride and/or chromium nitride and/or tungsten carbide.

A method for inhibiting alpha case on a titanium or titanium alloy article includes applying a ceramic coating to a surface of the article. The method further includes heating the article to a temperature of at least 800° F. while the ceramic coating is applied to the surface of the article. A method for manufacturing a titanium article that is substantially free of alpha case includes fabricating a preform by additive manufacturing, applying a ceramic coating to a surface of the preform, the ceramic coating having a nominal coating thickness of at least about 1 mil, subjecting the preform to hot isostatic pressing while the ceramic coating is applied to the surface, and removing the ceramic coating after hot isostatic pressing.