A multi-material three-dimensional printing apparatus is provided. The provided apparatus includes two or more print stations. Each of the print stations includes a substrate, a transportation device, a dispersion device, a compaction device, a printing device, a fixing device, and a fluidized materials removal device. The apparatus also includes an assembly apparatus in communication with the two or more print stations via the transportation device. The apparatus also includes one or more transfer devices in communication with the assembly apparatus. The apparatus also includes a computing and controlling device configured to control the operations of the two or more print stations, the assembly apparatus and the one or more transfer devices.

Devices, systems, and methods are directed to the use of vapor phase change in binder jetting processes for forming three-dimensional objects. In general, a vapor of a first fluid may be directed to a layer of a powder spread across a build volume. The vapor may condense to reduce mobility of the particles of the powder of the layer. For example, the condensing vapor may reduce the likelihood of particle ejection from the layer and, thus, may reduce the likelihood of clogging or otherwise degrading a printhead used to jet a second fluid (e.g., a binder) to the layer. Further, or instead, the condensing vapor may increase the density of the powder in the layer which, when repeated over a plurality of layers forming a three-dimensional object, may reduce the likelihood of slumping of the part during sintering.

According to one aspect, there is provided apparatus for forming a layer of build material for three-dimensional printing. The apparatus comprises a spreader to spread a volume of build material to form a layer of build material on a build platform, wherein at least one end of the spreader is to remain a constant distance from a build material retaining wall in proximity to at least one edge of the build platform as the spreader is moved over the surface of the build platform, and further wherein at least a portion of the spreader is below the top of the retaining wall.

According to one aspect, there is provided apparatus for forming a layer of build material for three-dimensional printing. The apparatus comprises a spreader to spread a volume of build material to form a layer of build material on a build platform, wherein at least one end of the spreader is to remain a constant distance from a build material retaining wall in proximity to at least one edge of the build platform as the spreader is moved over the surface of the build platform, and further wherein at least a portion of the spreader is below the top of the retaining wall.

According to one aspect, there is provided apparatus for forming a layer of build material for three-dimensional printing. The apparatus comprises a spreader to spread a volume of build material to form a layer of build material on a build platform, wherein at least one end of the spreader is to remain a constant distance from a build material retaining wall in proximity to at least one edge of the build platform as the spreader is moved over the surface of the build platform, and further wherein at least a portion of the spreader is below the top of the retaining wall.

A method of forming a vitreous bond abrasive article is presented that includes receiving, by a manufacturing device having one or more processors, a digital object comprising data specifying a plurality of layers of a vitreous bond abrasive article precursor. The vitreous bond abrasive article precursor includes abrasive particles bonded together by a vitreous bond precursor material and an organic compound. The vitreous bond abrasive article precursor further comprises at least one of: at least one tortuous cooling channel extending at least partially through the vitreous bond abrasive article precursor or at least one arcuate cooling channel extending at least partially through the vitreous bond abrasive article precursor. The method also includes generating, with the manufacturing device by an additive manufacturing process, the vitreous bond abrasive article precursor based on the digital object.

A build material dispensing device may include a material spreader to spread an amount of build material along a build platform, and at least one hopper for dispensing the build material. The at least one hopper dispenses a plurality of doses of the build material in front of the progression of the material spreader as the material spreader is moved over the build platform.

A build material dispensing device may include a material spreader to spread an amount of build material along a build platform, and at least one hopper for dispensing the build material. The at least one hopper dispenses a plurality of doses of the build material in front of the progression of the material spreader as the material spreader is moved over the build platform.

In a three-dimensional printing method example, a liquid functional agent is selectively applied. The liquid functional agent includes an alloying agent. A metallic build material is applied. The liquid functional agent is selectively applied before the metallic build material, after the metallic build material, or both before and after the metallic build material. The liquid functional agent patterns the metallic build material to form a composite layer. At least some of the metallic build material is exposed to energy to melt the at least some of the metallic build material to form a layer. Upon contact or after energy exposure, the alloying agent and the build material alter a composition of the composite layer.

A method of manufacturing a three-dimensionally shaped object includes a first powder-layer forming process in which a first portion of at least one thickness determining member forms a powder layer by moving in contact with powder, a solidifying process in which a solidified portion is formed in the powder layer formed in the first powder-layer forming process, a second powder-layer forming process, performed after the solidifying process, in which a second portion of the at least one thickness determining member forms a powder layer by moving in contact with the powder, and a renewal process performed between the first powder-layer forming process and the second powder-layer forming process. In the renewal process, the portion having been in contact with the powder is renewed such that the second portion is different from the first portion.