The Johns Hopkins University

Steven M Storck

Christopher M Peitsch

Morgana M Trexler

Salahudin M Nimer

Andrew M Lennon

Zachary R Ulbig

Joseph J Sopcisak

Ian D McCue

Rengaswamy Srinivasan

Paul J Biermann

Jeffrey P Maranchi

Joseph A Miragliotta

Kenneth R Grossman

Andrew C Merkle

Adam J Maisano

Matthew G Bevan

Jeffrey M Paulson

Scott A Shuler

Catherine M Carneal

Douglas B Trigg

Jarod C Gagnon

Vanessa D Alphonse

Kathleen M Perrino

Korine A Ohiri

Michael J Presley

Quang T Luong

Robert K Mueller

Ryan H Carter

Nathan G Drenkow

Mark A Athey

Brendan P Croom

Salahudin N Nimer

Additive manufacturing processes, systems and three-dimensional articles include the formation of voxels and/or portions of three-dimensional articles with different properties relative to other voxels and/or portions. The processes generally include changing one or more laser beam parameters including power level, exposure time, hatch spacing, point distance, velocity, and energy density during the formation of selected voxels and/or portions of the three-dimensional articles. Also disclosed are processes that include an additive manufacturing process that provides localized secondary heat treatment of certain voxels and/or regions at a temperature below the melting point of the three-dimensional article but high enough to effect a localized property change.

Localized tailoring of three-dimensional articles via additive manufacturing

A method for monitoring and analyzing an additive manufacturing process includes heating a melt zone to fuse an additive media with an active layer to build a part being manufactured based on a part design model, capturing raw melt data of the melt zone, and generating an active layer dataset that is spatially defined. The method may also include analyzing the active layer dataset with respect to a plurality of defect signatures within a defect signature library. The defect signature library may be predefined based on a machine learning processing of historical sensor datasets with corresponding ground truth datasets. The method may also include detecting a defect in the part based on the analysis of the active layer dataset with respect to a plurality of defect signatures, simultaneously with the energy source acting upon the active layer of the part for manufacturing of the part.

Additive manufacturing with in situ defect detection

A rapid material development process for a powder bed fusion additive manufacturing (PBF AM) process generally utilizes a computational fluid dynamics (CFD) simulation to facilitate selection of a simulated parameter set, which can then be used in a design of experiments (DOE) to generate an orthogonal parameter space to predict an ideal parameter set. The orthogonal parameter space defined by the DOE can then be used to generate a multitude of reduced volume build samples using PBF AM with varying laser or electron beam parameters and/or feedstock chemistries. The reduced volume build samples are mechanically characterized using high throughput techniques and analyzed to provide an optimal parameter set for a 3D article or a validation sample, which provides an increased understanding of the parameters and their independent and confounding effects on defects and microstructure. Additionally, machine learning techniques can be used to optimize for future parameter selection by modeling the relationship between input processing parameters and outputs of material characterization.

Rapid material development process for additive manufactured materials

A method for printing a semiconductor material includes depositing a molten metal onto a substrate in an enclosed chamber to form a trace having a maximum height of 15 micrometers and/or a maximum width of 25 micrometers to 10 millimeters and/or a thin film having a maximum height of 15 micrometers. The method further includes reacting the molten metal with a gas phase species in the enclosed chamber to form the semiconductor material. The depositing the molten metal includes depositing a metal composition including the molten metal and an etchant or depositing the etchant separate from the molten metal in the enclosed chamber.

Method for printing wide bandgap semiconductor materials

A system provided herein may be configured to evaluate helmet performance. The system may include an impact assembly that includes a stationary post operably coupled to one or more stationary load cells and a plurality of modular headforms. Each modular headform may include a first side and a second side configured to lock together around the impact assembly and receive a helmet. The modular headform may determine a position of the helmet relative to the one or more stationary load cells. Furthermore, the one or more stationary load cells may be configured to measure impact force at a position where one of the plurality of the modular headforms are operably coupled to the impact assembly. Additionally, each of the plurality of modular headforms correspond to a position in relation to the impact assembly to measure the impact force to the one or more load cells at a predefined number of impact locations on the helmet to evaluate the performance of the helmet.

System and method for evaluation of helmet performance

Functionalized metallic feedstock and three-dimensional articles formed therefrom via an additive manufacturing process are provided. The functionalized metallic feedstock includes a plurality of discrete metallic substrates including a first metallic substrate having a first surface area, in which at least a portion of the first surface area comprises a functionalizing agent selected to render the first metallic substrate resistant to corrosion.

Empowering additive manufacturing metals and alloys against localized three-dimensional corrosion

Electromagnetic shielding systems, apparatuses, and method are provided. One apparatus is an example free-space absorber metamaterial that includes a first array of patches disposed at a first plane, a conductive backplane disposed at a structural surface plane, and a first dielectric spacer disposed between the first array of patches and the conductive backplane. A first bandwidth of absorption for the free-space absorber metamaterial may be based on the area of a patch in the first array of patches, the first electrical resistance of a patch in the first array of patches, and the first gap distance taken between the first array of patches and the conductive backplane.

Electromagnetic energy shielding systems, apparatuses, and methods

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Timonium, MD, United States of America

Steven M Storck