The present disclosure describes three-dimensional (3D) printing apparatuses, processes, software, and systems for producing high quality 3D objects. Described herein are printing apparatuses that facilitate control of water vapor concentration during one or more printing operations.

A system and method of monitoring a powder-bed additive manufacturing process is provided where a layer of additive powder is fused using an energy source and electromagnetic emission signals are measured by a melt pool monitoring system to monitor the print process. The measured emission signals are analyzed to identify outlier emissions and clusters of outliers are identified by assessing the spatial proximity of the outlier emissions, e.g., using clustering algorithms, spatial control charts, etc. An alert may be provided or a process adjustment may be made when a cluster is identified or when a magnitude of a cluster exceeds a predetermined cluster threshold.

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.

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.

A build region limitation unit for an additive manufacturing apparatus includes a movable unit fixed to a build table and a non-movable unit placed on a base frame. The movable unit includes a first anti-scattering frame provided to protrude upward. The non-movable unit includes a flat plate that covers a first build region with a portion other than an opening and forms a second build region, and a second anti-scattering frame that is provided to protrude downward at an outer periphery of the opening. The first anti-scattering frame surrounds the second anti-scattering frame with a gap therebetween.

A method for dynamically controlling layer thickness during an additive manufacturing process of building a block including an object with layers of powder material, detecting a height of the block after each layer is compacted, determining a delta between the detected height and a height in a computer model defining slices of the block and compensating for the determined delta in subsequent cycles. A cycle in the additive manufacturing process includes selectively printing a layer pattern, spreading a powder layer over the layer pattern with a spreader and compacting the powder layer with the layer pattern.

A method for dynamically controlling layer thickness during an additive manufacturing process of building a block including an object with layers of powder material, detecting a height of the block after each layer is compacted, determining a delta between the detected height and a height in a computer model defining slices of the block and compensating for the determined delta in subsequent cycles. A cycle in the additive manufacturing process includes selectively printing a layer pattern, spreading a powder layer over the layer pattern with a spreader and compacting the powder layer with the layer pattern.

Described is an additive manufacturing apparatus for additive manufacturing of three dimensional objects, said apparatus comprises a powder distribution unit movable across a build area for applying a layer of powder material thereon and a solidification device for selectively solidifying the applied powder layer at positions corresponding to a cross section of the object to be manufactured. Said powder distribution unit comprises at least a first and a second powder distributors essentially in parallel with each other and extending in a first direction, said first and second powder distributors are arranged to be adjustably spaced apart in a second direction transversely to said first direction which second direction is essentially in parallel with the direction of movement of said powder distribution unit over said build area.

Described is an additive manufacturing apparatus for additive manufacturing of three dimensional objects, said apparatus comprises a powder distribution unit movable across a build area for applying a layer of powder material thereon and a solidification device for selectively solidifying the applied powder layer at positions corresponding to a cross section of the object to be manufactured. Said powder distribution unit comprises at least a first and a second powder distributors essentially in parallel with each other and extending in a first direction, said first and second powder distributors are arranged to be adjustably spaced apart in a second direction transversely to said first direction which second direction is essentially in parallel with the direction of movement of said powder distribution unit over said build area.

The present disclosure provides three-dimensional (3D) objects, 3D printing processes, as well as methods, apparatuses and systems for the production of a 3D object. Methods, apparatuses and systems of the present disclosure may reduce or eliminate the need for auxiliary supports. The present disclosure provides three dimensional (3D) objects printed utilizing the printing processes, methods, apparatuses and systems described herein.