Estimation algorithms, methods, and systems are provided that estimate the internal temperatures inside of a part being built using powder bed fusion (PBF). Closed-loop state estimation is applied to the problem of monitoring temperature fields within parts during the PBF build process. A simplified linear time-invariant (LTI) model of PBF thermal physics with the properties of stability, controllability and observability is presented. In some aspects, an Ensemble Kalman Filter is applied to the model. Linear time-varying (LTV) systems are also contemplated.

A novel process for creating porous structures via powder bed fusion additive manufacturing is provided. The process reduces the computational requirement for generation of the porous structure geometry and for processing the porous structure geometry to generate CNC code. The process provides reduced file size for CNC code and avoids large files which may exceed capacity of manufacturing machines. The process also significantly reduces the time required to sinter the porous structure on a powder bed fusion manufacturing machine.

The invention is directed to a powder supply system (1) for use in an apparatus (100) for producing a three-dimensional work piece by irradiating layers of a raw material powder (4) with electromagnetic or particle radiation. The powder supply system (1) comprises a circuit line (7) configured to conduct a gas stream (9), a conveying device (19) configured to convey the gas stream (9) through the circuit line (7), a powder doser (8) configured to introduce a desired dose of raw material powder (4) into the gas stream (9) flowing through the circuit line (7), a measuring unit (15) configured to measure at least one of a pressure and a volume flow in the circuit line (7) at a position downstream of the powder doser (8), and a control unit (40) configured to control the powder doser (8) based on at least one of a pressure value and a volume flow value measured by the measuring unit (15) in such a manner that the at least one of the pressure value and the volume flow value measured by the measuring unit (15) is within a predetermined range.

The invention is directed to a powder supply system (1) for use in an apparatus (100) for producing a three-dimensional work piece by irradiating layers of a raw material powder (4) with electromagnetic or particle radiation. The powder supply system (1) comprises a circuit line (7) configured to conduct a gas stream (9), a conveying device (19) configured to convey the gas stream (9) through the circuit line (7), a powder doser (8) configured to introduce a desired dose of raw material powder (4) into the gas stream (9) flowing through the circuit line (7), a measuring unit (15) configured to measure at least one of a pressure and a volume flow in the circuit line (7) at a position downstream of the powder doser (8), and a control unit (40) configured to control the powder doser (8) based on at least one of a pressure value and a volume flow value measured by the measuring unit (15) in such a manner that the at least one of the pressure value and the volume flow value measured by the measuring unit (15) is within a predetermined range.

According to one example there is provided a non-transitory computer readable storage medium comprising instructions that, when executed by a processor, cause the processor to: obtain an object model; analyse the object model; obtain characteristics of an interface agent; generate a modified object model comprising a support structure and an interface between the support structure and the object, the interface being such that after generation of a 3D printed green part and after sintering thereof, the support structure may be released with a predetermined force; and controlling a 3D printer to generate a 3D printed green part based on the modified object model.

A method for training a machine learning engine for modeling of a physical system includes receiving process data representing measurements of a physical system. The method includes applying a transform to values of the at least two variables of the process data to generate a dimensionless parameter having a parameter value corresponding to each measurement of the physical system for the at least two variables. The method includes training the machine learning engine using a set of generated training data including the non-dimensionalized parameter, to output a prediction of a value of a physical effect of the physical system for values of the variables that are not included in the process data. The method includes controlling an additive manufacturing process for the material by setting the at least one physical property to the value of the at least one process variable during fabrication of a part.

According to an example, a method of processing a print job in an additive manufacturing system comprises: applying a geometrical calibration to the print job to obtain a calibrated job; determining a height of a set of print job powder layers to be formed to generate the objects based on the calibrated print job; determining a height of a set of warming powder layers to be formed prior to the set of print job powder layers; determining an ideal height of a set of annealing powder layers to be formed after to the set of print job powder layers; and determining if the combined height of the sets of layers exceeds the maximum available height.

In some examples, a method comprises obtaining, by an additive manufacturing device, a file compatible with the additive manufacturing device, the file comprising representations of objects and a support structure for the objects, the representation of the support structure having an identifier for identifying the support structure; and the additive manufacturing device using an additive manufacturing process and the file to manufacture the objects, the support structure, and the identifier for identifying the support structure.

A build plate-clamping assembly may include a work station having a build plate-receiving surface and a lock-pin extending from the build plate-receiving surface of the work station. The lock-pin may include a hollow pin body, a piston disposed within the hollow pin body, with the piston axially movable from a retracted position to an actuated position, and a plurality of detents, with the plurality of detents radially extensible through respective ones of a plurality of detent-apertures in the hollow pin body responsive to the piston having been axially moved to the actuated position. A methods of working on workpieces may include lockingly engaging a build plate at a first work station, performing a first work-step, releasing the build plate from the first work station, lockingly engaging the build plate at a second work station, and performing a second work-step. An additive manufacturing system may include a vision system with a first build plate-receiving surface and an additive manufacturing machine with a second build plate-receiving surface.

An ejector for an additive manufacturing printing system is disclosed, including an ejector body having a nozzle, a heating element to heat a solid printing material in the ejector, causing the solid printing material to change to a liquid printing material, and a piston disposed within the ejector body capable of translational motion. The ejector may include a segmented solenoid coil wrapped at least partially around the ejector body, which may be powered to cause the piston to translate along a longitudinal axis of the ejector thereby causing one or more drops of the liquid printing material to be jetted out of the nozzle. A method of ejecting liquid from an ejector is also disclosed, including melting a printing material within an ejector to form a liquid printing material, and moving a piston towards an ejector nozzle, and ejecting a drop of liquid printing material from the ejector nozzle.