Abstract: 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.

Abstract: This invention teaches a quality assurance system for additive manufacturing. This invention teaches a multi-sensor, real-time quality system including sensors, affiliated hardware, and data processing algorithms that are Lagrangian-Eulerian with respect to the reference frames of its associated input measurements. The quality system for Additive Manufacturing is capable of measuring true in-process state variables associated with an additive manufacturing process, i.e. those in-process variables that define a feasible process space within which the process is deemed nominal. The in-process state variables can also be correlated to the part structure or microstructure and can then be useful in identifying particular locations within the part likely to include defects.

Abstract: This invention teaches a quality assurance system for additive manufacturing. This invention teaches a multi-sensor, real-time quality system including sensors, affiliated hardware, and data processing algorithms that are Lagrangian-Eulerian with respect to the reference frames of its associated input measurements. The quality system for Additive Manufacturing is capable of measuring true in-process state variables associated with an additive manufacturing process, i.e. those in-process variables that define a feasible process space within which the process is deemed nominal. The in-process state variables can also be correlated to the part structure or microstructure and can then be useful in identifying particular locations within the part likely to include defects.

Abstract: 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.

Abstract: This disclosure describes various system and methods for monitoring photons emitted by a heat source of an additive manufacturing device. Sensor data recorded while monitoring the photons can be used to predict metallurgical, mechanical and geometrical properties of a part produced during an additive manufacturing operation. In some embodiments, a test pattern can be used to calibrate an additive manufacturing device.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: This invention teaches a quality assurance system for additive manufacturing. This invention teaches a multi-sensor, real-time quality system including sensors, affiliated hardware, and data processing algorithms that are Lagrangian-Eulerian with respect to the reference frames of its associated input measurements. The quality system for Additive Manufacturing is capable of measuring true in-process state variables associated with an additive manufacturing process, i.e. those in-process variables that define a feasible process space within which the process is deemed nominal. The in-process state variables can also be correlated to the part structure or microstructure and can then be useful in identifying particular locations within the part likely to include defects.

Abstract: The present invention provides a feature extraction system that extracts geometrical features of a part using in-process data acquired during an additive manufacturing process. The geometric features are extracted by applying a number of image processing operations to images taken of a powder bed during the additive manufacturing process. In this way, both internal and external geometries of the part can be characterized. In some embodiments, geometric feature extraction can be used in conjunction with other part characterizing operations, such as for example, thermal characterization processes.

Abstract: A new method of process control for fusion welding maintains a controlled weld pool size or volume, for example in some applications a substantially constant weld pool size or volume. The invention comprises a method of linking machine and process variables to the weld pool size or volume in real time, thereby enabling constant weld pool volume control. The invention further comprises a method of using thermal inverse models to rapidly process real-time data and enable models-based control of welding processes so as to implement constant weld pool volume control.

Abstract: The present inventions provide methods of manufacturing methods for case metallic materials for munitions that have high enthalpic energy release and controlled fragmentation and breakup enabling fragment speeds up to twice what is otherwise possible in explosively driven metal systems, and munitions made by such methods. Embodiments of the invention involve the thixotropic processing of energetic materials such as aluminum together with high density materials such as tantalum or tungsten to achieve material microstructures with a bulk density equivalent to steel, but with the energy release potential of materials such as finely dispersed aluminum powders.

Abstract: A projectile formed from dissimilar materials. The projectile includes a metallurgical interlayer that joins the dissimilar materials together. The metallurgical interlayer also matches the shock impedance of the two materials to prevent delamination during launch and during impact.

Abstract: A new method of process control for fusion welding maintains a controlled weld pool size or volume, for example in some applications a substantially constant weld pool size or volume. The invention comprises a method of linking machine and process variables to the weld pool size or volume in real time, thereby enabling constant weld pool volume control. The invention further comprises a method of using thermal inverse models to rapidly process real-time data and enable models-based control of welding processes so as to implement constant weld pool volume control.

Abstract: A new method of process control for fusion welding maintains a controlled weld pool size or volume, for example in some applications a substantially constant weld pool size or volume. The invention comprises a method of linking machine and process variables to the weld pool size or volume in real time, thereby enabling constant weld pool volume control. The invention further comprises a method of using thermal inverse models to rapidly process real-time data and enable models-based control of welding processes so as to implement constant weld pool volume control.

Abstract: The present inventions provide methods of manufacturing methods for case metallic materials for munitions that have high enthalpic energy release and controlled fragmentation and breakup enabling fragment speeds up to twice what is otherwise possible in explosively driven metal systems, and munitions made by such methods. Embodiments of the invention involve the thixotropic processing of energetic materials such as aluminum together with high density materials such as tantalum or tungsten to achieve material microstructures with a bulk density equivalent to steel, but with the energy release potential of materials such as finely dispersed aluminum powders.

Abstract: A method for determining the quality of an examined weld joint comprising the steps of providing acoustical data from the examined weld joint, and performing a neural network operation on the acoustical data determine the quality of the examined weld joint produced by a friction weld process. The neural network may be trained by the steps of providing acoustical data and observable data from at least one test weld joint, and training the neural network based on the acoustical data and observable data to form a trained neural network so that the trained neural network is capable of determining the quality of a examined weld joint based on acoustical data from the examined weld joint. In addition, an apparatus having a housing, acoustical sensors mounted therein, and means for mounting the housing on a friction weld device so that the acoustical sensors do not contact the weld joint. The apparatus may sample the acoustical data necessary for the neural network to determine the quality of a weld joint.