Polycrystalline cubic boron nitride, PCBN, material and methods of making PCBN. A method includes providing a matrix precursor powder comprising particles having an average particle size no greater than 250 nm, providing a cubic boron nitride, cBN, powder comprising particles of cBN having an average particle size of at least 0.2 intimately mixing the matrix precursor powder and the cBN powder, and sintering the intimately mixed powders at a temperature of at least 1100° C. and a pressure of at least 3.5 GPa to form the PCBN material comprising particles of cubic boron nitride, cBN dispersed in a matrix material.

In one example in accordance with the present disclosure, an additive manufacturing platform is described. The additive manufacturing platform includes a vibrating bed on which a volume of build material is to be disposed. The bed is to vibrate to remove excess build material and operates in at least two extraction modes during a build material extraction period. The additive manufacturing platform also includes a non-vibrating frame to support the vibrating bed.

In one example in accordance with the present disclosure, an additive manufacturing platform is described. The additive manufacturing platform includes a vibrating bed on which a volume of build material is to be disposed. The bed is to vibrate to remove excess build material and operates in at least two extraction modes during a build material extraction period. The additive manufacturing platform also includes a non-vibrating frame to support the vibrating bed.

A dispensing system for an additive manufacturing apparatus includes a frame, a powder reservoir, an agitator and an array of dispensing units positioned below the powder reservoir. The powder reservoir has a first width along a primary axis, and includes a lower portion and an upper portion that is wider than the lower portion along a second axis perpendicular to the primary axis. The agitator is positioned in the upper portion of the powder reservoir. Each dispensing unit includes a nozzle block that has a passage therethrough that defines a nozzle and provides a respective path for the powder to flow from the powder reservoir to the nozzle, and a valve positioned in the passage in the nozzle block to controllably release powder through the nozzle.

A dispensing system for an additive manufacturing apparatus includes a frame, a powder reservoir, an agitator and an array of dispensing units positioned below the powder reservoir. The powder reservoir has a first width along a primary axis, and includes a lower portion and an upper portion that is wider than the lower portion along a second axis perpendicular to the primary axis. The agitator is positioned in the upper portion of the powder reservoir. Each dispensing unit includes a nozzle block that has a passage therethrough that defines a nozzle and provides a respective path for the powder to flow from the powder reservoir to the nozzle, and a valve positioned in the passage in the nozzle block to controllably release powder through the nozzle.

A printing apparatus for printing a three-dimensional object comprising an operative surface, at least one supply hopper for depositing layers of powder onto the operative surface and an energy source for emitting at least one energy beam onto the layers of powder. The supply hopper and energy source are configured such that when a topmost layer of powder is being deposited onto an underlying layer of powder on the operative surface, the direction travelled by the supply hopper when depositing the topmost layer is different to the direction travelled by the supply hopper when depositing the underlying layer, and at least one energy beam is emitted onto the topmost layer and at least one further energy beam is emitted onto the underlying layer, simultaneously, to melt, fuse or sinter the topmost and underlying layers.

A printing apparatus for printing a three-dimensional object comprising an operative surface, at least one supply hopper for depositing layers of powder onto the operative surface and an energy source for emitting at least one energy beam onto the layers of powder. The supply hopper and energy source are configured such that when a topmost layer of powder is being deposited onto an underlying layer of powder on the operative surface, the direction travelled by the supply hopper when depositing the topmost layer is different to the direction travelled by the supply hopper when depositing the underlying layer, and at least one energy beam is emitted onto the topmost layer and at least one further energy beam is emitted onto the underlying layer, simultaneously, to melt, fuse or sinter the topmost and underlying layers.

Support substrates are used in certain additive fabrication processes to permit processing of an object. For additive fabrication processes with materials that are sintered into a final part, a multi-layer support substrate of interleaved support and interface layers is fabricated to support an object while reducing an impact of friction on shrinkage of the part during the sintering process.

Support substrates are used in certain additive fabrication processes to permit processing of an object. For additive fabrication processes with materials that are sintered into a final part, a multi-layer support substrate of interleaved support and interface layers is fabricated to support an object while reducing an impact of friction on shrinkage of the part during the sintering process.

An additive manufacturing process which comprises carrying out an additive manufacturing build process to create a build cake. The build cake comprises a build object and non-solidified build material and the build object is built in a build location within the build cake. The build cake is supported on a tray which comprises a mesh having openings therethrough. The tray also includes an object region and a restraining feature to restrain a build object within the object region. The process comprises performing a decake operation in which non-solidified build material from the build cake passes through the openings of the mesh and the object moves into contact with the tray in the object region so that the object is restrained within the object region of the tray by the restraining feature.