A sintered Nd—Fe—B magnet comprising at least one light rare earth element having a weight content between 31 wt. % and 35 wt. %, at least one heavy rare earth element having a weight content of no more than 0.2 wt. %, B having a weight content between 0.95 wt. % and 1.2 wt. %, at least one additive including Ti and having a weight content between 1.31 wt. % and 7.2 wt. %, Fe as a balance, and impurities including C, O, and N. Ti has a weight content between 0.3 wt. % and 1 wt. % and forms a Titanium-Iron-Boron phase with Fe and Boron B and being present in the sintered Nd—Fe—B magnet between 0.86 vol. % and 2.85 vol. %. The C, O, and N satisfy 630 ppm≦1.2C+0.6O+N≦3680 ppm. The sintered Nd—Fe—B magnet has a squareness factor of at least 0.95.

An additive manufacturing apparatus comprises a processing chamber (100) defining a window (110) for receiving a laser beam and an optical module (10) The optical module is removably-mountable to the processing chamber for delivering the laser beam through the window. The optical module contains optical components for focusing and steering the laser beam and a controlled atmosphere can be maintained within the module.

An additive manufacturing apparatus comprises a processing chamber (100) defining a window (110) for receiving a laser beam and an optical module (10) The optical module is removably-mountable to the processing chamber for delivering the laser beam through the window. The optical module contains optical components for focusing and steering the laser beam and a controlled atmosphere can be maintained within the module.

Disclosed is a nano dispersion copper alloy with high air-tightness and low free oxygen content and a brief manufacturing process thereof, wherein alloy comprises the following components: Al.sub.2O.sub.3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion and then rotary forging; vacuumizing the sheath after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature of 450° C. to 550° C. and a pressure intensity of 40 Mpa to 60 Mpa for 3 hours to 5 hours. The dispersion copper prepared by the present disclosure has the advantages of low free oxygen content (≤15 ppm), high dimensional stability, good air-tightness and an air leakage rate≤1.0×10.sup.−10 Pa m.sup.3/s after hydrogen annealing.

Disclosed is a nano dispersion copper alloy with high air-tightness and low free oxygen content and a brief manufacturing process thereof, wherein alloy comprises the following components: Al.sub.2O.sub.3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion and then rotary forging; vacuumizing the sheath after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature of 450° C. to 550° C. and a pressure intensity of 40 Mpa to 60 Mpa for 3 hours to 5 hours. The dispersion copper prepared by the present disclosure has the advantages of low free oxygen content (≤15 ppm), high dimensional stability, good air-tightness and an air leakage rate≤1.0×10.sup.−10 Pa m.sup.3/s after hydrogen annealing.

An additive manufacturing (AM) system includes a housing defining a chamber, a build platform disposed in the chamber at a first elevation, and a lower gas inlet disposed at a second elevation and configured to supply a lower gas flow. The AM system includes a contoured surface extending between the lower gas inlet and the build platform to direct the lower gas flow from the second elevation at the lower gas inlet to the first elevation at the build platform, where the contoured surface discharges the lower gas flow in a direction substantially parallel to the build platform. The AM system also includes one or more gas delivery devices coupled to the lower gas inlet to regulate one or more flow characteristics of the lower gas flow, and a gas outlet configured to discharge the lower gas flow.

The present invention provides a high-strength and high-plasticity titanium matrix composite and a preparation method thereof. The preparation method includes: preparing high-oxygen hydride-dehydride titanium powder using a high-temperature rotary ball grinding treatment process, in which the prepared hydride-dehydride titanium powder has a particle size of 10-40 μm, and has an oxygen content of 0.8-1.5 wt. %; preparing high-purity ultra-fine oxygen adsorbent powder using a wet grinding method of high-energy vibration ball grinding treatment process; in which a purity of the oxygen adsorbent powder is ≥99.9%, and a particle size of the oxygen adsorbent powder is ≤8 μm; mixing the high-oxygen hydride-dehydride titanium powder with the oxygen adsorbent powder in a protective atmosphere, and then press-forming the powder obtained after mixing to obtain a raw material blank; and performing atmosphere protective sintering treatment on the raw material blank to obtain a titanium matrix composite. The method prepares a titanium matrix composite reinforced by in-situ self-generating multi-scale Ca—Ti—O, TiC, TiB particles. The microstructure and grains are effectively refined, and the strength and plasticity of the material are significantly improved.

The present disclosure provides three-dimensional (3D) printing systems, apparatuses, software, and devices for the production of at least one requested 3D object in a printing cycle, e.g., a control system. The 3D printing includes, or is operatively coupled to, a metrological detection system configured to facilitate assessment of at least one characteristic of the 3D printing, e.g., relating to height. The 3D printing includes synchronization of various operations, and resulting objects printed in the 3D printing system.

Provided is a stainless steel powder composition, which comprises Cr, Cu, Mn, Mo, Ni and Fe; wherein, based on a total weight of the stainless steel powder composition, a content of Cr is 20 wt% to 24 wt%, and a content of Cu is more than 0 wt% and less than or equal to 0.5 wt%, a content of Mn is more than 0 wt% and less than or equal to 2 wt%, a content of Mo is 2.25 wt% to 3 wt% and a content of Ni is 10 wt% to 15 wt%. When applying the stainless steel powder composition of the present invention to laser additive manufacturing (LAM), the produced stainless steel workpiece has enhanced tensile strength, thereby expanding the follow-up applications and increasing the commercial value.

Provided is a stainless steel powder composition, which comprises Cr, Cu, Mn, Mo, Ni and Fe; wherein, based on a total weight of the stainless steel powder composition, a content of Cr is 20 wt% to 24 wt%, and a content of Cu is more than 0 wt% and less than or equal to 0.5 wt%, a content of Mn is more than 0 wt% and less than or equal to 2 wt%, a content of Mo is 2.25 wt% to 3 wt% and a content of Ni is 10 wt% to 15 wt%. When applying the stainless steel powder composition of the present invention to laser additive manufacturing (LAM), the produced stainless steel workpiece has enhanced tensile strength, thereby expanding the follow-up applications and increasing the commercial value.