An additive manufacturing system comprises an apparatus arranged to distribute layer of metallic powder across a build plane and a power source arranged to emit a beam of energy at the build plane and fuse the metallic powder into a portion of a part. The system includes a processor configured to steer the beam of energy across the build plane and receive data generated by one or more sensors that detect electromagnetic energy emitted from the build plane when the beam of energy fuses the metallic powder. The received data is converted into one or more parameters that indicate one or more conditions at the build plane while the beam of energy fuses the metallic powder. The one or more parameters are used as input into a machine learning algorithm to detect one or more defects in the fused metallic powder.
An additive manufacturing system includes a work region having a layer of metallic powder distributed across at least a portion of the work region. The system further includes a power source, a scanning and focusing system and a processor. The processor is configured to control the power source to emit a beam of energy at a power level and to manipulate the beam of energy across the work region in a plurality of build tracks to form a part from the fused metallic powder. The processor further determines a cooling rate at a termination of each of the plurality of build tracks and controls the power level of the power source in response to the determined cooling rate.
An additive manufacturing system comprises a build plane and an energy source configured to direct energy onto a work region of the build plane. An optical detector is configured to receive one or more optical signals from the work region. An optical filter is positioned between the work region and the optical detector, wherein the optical filter includes a first partially transmissive polarized filter having a first polarization axis and a second partially transmissive polarized filter having a second polarization axis. The first polarization axis is rotationally offset from the second polarization axis approximately 90 degrees. The optical filter improves the signal to noise ratio of the optical sensors..
B33Y 30/00 - ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - Details thereof or accessories therefor
B33Y 50/02 - Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
4.
PHOTODETECTOR ARRAY FOR ADDITIVE MANUFACTURING OPERATIONS
This disclosure describes an additive manufacturing system that includes a build plane having a first region and a second region. Multiple energy source can be positioned above the build plane and configured to direct energy into the first and second regions of the build plane. The system includes optical sensors configured to monitor an intensity of light emitted from the energy sources. A processor associated with the additive manufacturing system is configured to adjust the sensor outputs in response to the energy sources coming into close proximity.
This disclosure describes various methods and apparatus for characterizing an additive manufacturing process. A method for characterizing the additive manufacturing process can include generating scans of an energy source across a build plane; measuring an amount of energy radiated from the build plane during each of the scans using an optical sensing system that monitors two discrete wavelengths associated with a blackbody radiation curve of the layer of powder; determining temperature variations for an area of the build plane traversed by the scans based upon a ratio of sensor readings taken at the two discrete wavelengths; determining that the temperature variations are outside a threshold range of values; and thereafter, adjusting subsequent scans of the energy source across or proximate the area of the build plane.
B29C 64/153 - Processes of additive manufacturing using only solid materials using layers of powder being selectively joined, e.g. by selective laser sintering or melting
B29C 64/386 - Data acquisition or data processing for additive manufacturing
B29C 64/393 - Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
B33Y 50/02 - Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
B22F 3/105 - Sintering only by using electric current, laser radiation or plasma
6.
SYSTEMS AND METHODS FOR MEASURING RADIATED THERMAL ENERGY DURING AN ADDITIVE MANUFACTURING OPERATION
This disclosure describes various methods and apparatus for characterizing an additive manufacturing process. A method for characterizing the additive manufacturing process can include generating scans of an energy source across a build plane; measuring an amount of energy radiated from the build plane during each of the scans using an optical sensor; determining an area of the build plane traversed during the scans; determining a thermal energy density for the area of the build plane traversed by the scans based upon the amount of energy radiated and the area of the build plane traversed by the scans; mapping the thermal energy density to one or more location of the build plane; determining that the thermal energy density is characterized by a density outside a range of density values; and thereafter, adjusting subsequent scans of the energy source across or proximate the one or more locations of the build plane.
B23K 26/08 - Devices involving relative movement between laser beam and workpiece
B23K 26/14 - Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
B23K 26/34 - Laser welding for purposes other than joining
B33Y 50/02 - Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
The disclosed embodiments relate to the monitoring and control of additive manufacturing. In particular, a method is shown for removing errors inherent in thermal measurement equipment so that the presence of errors in a product build operation can be identified and acted upon with greater precision. Instead of monitoring a grid of discrete locations on the build plane with a temperature sensor, the intensity, duration and in some cases position of each scan is recorded in order to characterize one or more build operations.
B22F 3/105 - Sintering only by using electric current, laser radiation or plasma
B33Y 50/02 - Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
G01N 21/71 - Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
Various ways in which material property variations of raw materials used in additive manufacturing can be identified and accounted for are described. In some embodiments, the raw material can take the form of powdered metal. The powdered metal can have any number of variations including the following: particle size variation, contamination, particle composition and particle shape. Prior to utilizing the powders in an additive manufacturing operation, the powders can be inspected for variations. Variations and inconsistencies in the powder can also be identified by monitoring an additive manufacturing with one or more sensors. In some embodiments, the additive manufacturing process can be adjusted in real-time to adjust for inconsistencies in the powdered metal.
B29C 67/00 - Shaping techniques not covered by groups , or
B29C 41/02 - Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
9.
MULTI-SENSOR QUALITY INFERENCE AND CONTROL FOR ADDITIVE MANUFACTURING PROCESSES
This invention teaches a multi-sensor quality inference system for additive manufacturing. This invention still further teaches a quality system that is capable of discerning and addressing three quality issues: i) process anomalies, or extreme unpredictable events uncorrelated to process inputs; ii) process variations, or difference between desired process parameters and actual operating conditions; and iii) material structure and properties, or the quality of the resultant material created by the Additive Manufacturing process. This invention further teaches experimental observations of the Additive Manufacturing process made only in a Lagrangian frame of reference. This invention even further teaches the use of the gathered sensor data to evaluate and control additive manufacturing operations in real time.
An optical manufacturing process sensing and status indication system is taught that is able to utilize optical emissions from a manufacturing process to infer the state of the process. In one case, it is able to use these optical emissions to distinguish thermal phenomena on two timescales and to perform feature extraction and classification so that nominal process conditions may be uniquely distinguished from off-nominal process conditions at a given instant in time or over a sequential series of instants in time occurring over the duration of the manufacturing process. In other case, it is able to utilize these optical emissions to derive corresponding spectra and identify features within those spectra so that nominal process conditions may be uniquely distinguished from off-nominal process conditions at a given instant in time or over a sequential series of instants in time occurring over the duration of the manufacturing process.
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