Additive Manufacturing of Large-scale Metallic Components: Novel Applications II
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee
Program Organizers: Sougata Roy, Iowa State University; Sneha Prabha Narra, Carnegie Mellon University; Andrzej Nycz, Oak Ridge National Laboratory; Yousub Lee, Oak Ridge National Laboratory; Chantal Sudbrack, National Energy Technology Laboratory; Albert To, University of Pittsburgh; Yashwanth Bandari, AddiTec Technologies LLC
Thursday 2:00 PM
March 23, 2023
Room: 25A
Location: SDCC
Session Chair: Kyle Johnson, Sandia National Laboratories
2:00 PM
Distortion Compensation for Metal Additive Manufacturing: Theresa Honein1; Collette Gillaspie1; Mehmet Sirtalan1; Kyle Johnson1; Carl Herriott1; Michael Stender1; Ellen Wagman1; Richard Deering2; 1Sandia National Laboratories; 2Kansas City National Security Campus
Residual stress and distortion are primary obstacles to metal additive manufacturing (AM). The two phenomena are intricately linked, and both are material-, process-, and geometry-dependent. Distortion can lead to significant deviations from nominal CAD geometries, compromising the quality of the as-built component. As a result, AM-induced distortion can invalidate the precision of critical structures. Therefore, an efficient numerical distortion compensation workflow informed by high fidelity thermomechanical simulations has been developed to predict residual stress and distortion for the purpose of an inverse analysis. The iterative analysis modifies CAD geometries based on mapped distortions. Progress to date will be discussed, and comparisons before and after compensation will be presented. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.
2:20 PM
Effect of Aging and Quenching Media on the Mechanical Behavior of AlSi10Mg: Bryan Mcenerney1; R. Dillon1; Molly Hwang1; John Paul Borgonia1; Richard Otis1; 1NASA Jet Propulsion Laboratory
The heat treatment of AlSi10Mg produced by laser powder bed fusion was investigated using various quenchant materials and aging conditions, based upon prior work demonstrating the viability of water quenching and controlled aging process. Water, glycol, and helium gas quenching were tested on a series of ASTM E8 compact tension testing coupons and the results demonstrated the best statistical strength and reduced scatter from an 18% glycol quenching approach with a 10 hour hold at 158 °C, with typical properties validated through testing over a range of -125 °C – 125 °C range.
2:40 PM
In Situ Monitoring of Residual Stress during Heat Treatment of High Strength Additively Manufactured Steel via Laser Ultrasound Measurements: Franklyn Kellogg1; Stephen Cluff1; Josh Taggart-Scarff1; Brandon McWilliams1; 1US Army DEVCOM ARL
Residual stress is a problem for laser powder bed fusion additive manufacturing (LPBF AM) that can cause part failure during building or removing the part from the build plate. It can be mitigated through part design or heat treating after building. However, determining proper heat treatments adds extra complexity to the build process. In this study, samples of a high strength steel alloy were made by LPBF AM. Samples were stretched on an Instron at room temperature to induce known levels of strain prior to being held at an elevated temperature for stress relief using a Gleeble 3800. While at temperature, laser ultrasound measurements (LUMET) were used to track changes within the sample during heating. Samples were examined microscopically after heating to determine if changes in the ultrasound signal were caused by microstructural changes, such as grain growth, or due to changes to the stress-strain state within the sample.
3:00 PM
Comparing the Fatigue Behavior of Laser Powder Bed Fused Ti-6Al-4V: Single-laser vs. Dual-laser: Seungjong Lee1; Jiwon Jung1; Shuai Shao1; Donald Godfrey2; Nima Shamsaei1; 1Auburn University; 2SLM Solutions NA, Inc.
Laser powder bed fusion (L-PBF) systems with large build volumes typically subdivide the build area into subregions, with each of them being covered by a different laser. To ensure redundancy, these regions also have overlaps where parts are simultaneously scanned by at least two lasers. The single-laser and dual-laser fabricated parts may experience different thermal histories, resulting in different micro-/defect- structures and thus different mechanical properties. In this study, the fatigue behavior of single-laser and dual-laser Ti-6Al-4V specimens fabricated in a quad-laser L-PBF system was investigated. The specimens were built in two different orientations, vertically and horizontally, hot isostatically pressed, and subjected to uniaxial, fully-reversed fatigue tests in force-controlled mode. The results indicate that the microstructure, porosity, and fatigue behavior of single-laser and dual-laser are not significantly different. This may be ascribed to the defects being minimized and microstructure being homogenized by the heat treatments including hot isostatically pressing.
3:20 PM Break
3:35 PM
A Microstructure Development Model for Wire Arc Additively Manufactured Haynes 282: Sophie Hill1; Jonah Klemm-Toole1; Anthony Petrella1; 1Colorado School of Mines
Gas metal arc welding (GMAW) based wire arc additive manufacturing (WAAM) offers several benefits including high deposition rates and low equipment cost to manufacture large structural components. In high temperature structural applications, such as power generation, precipitation strengthened Ni-based alloys are often used. In this presentation, we discuss our work focused on developing models capable of predicting the microstructure of WAAM Haynes 282. We combine a dendrite growth model with heat transfer simulations to predict primary and secondary dendrite arm spacing, dendrite growth morphology, and elemental segregation in the as-built condition. Methods to calibrate our models with experimental measurements are discussed.
3:55 PM
Assessing the Properties of Stainless Steels Fabricated via Wire-arc Additive Manufacturing: Ching-Hao (Cliff) Yu1; Shiqi Zheng1; Yu-Keng Lin1; Alberico Talignani1; Xiaochun Li1; Jenn-Ming Yang1; Yinmin (Morris) Wang1; 1University of California, Los Angeles
The birth of additive manufacturing (AM) technology and its development have presented potential opportunities to overcome the traditional manufacturing limitations while evoking attractive material properties. Multiple sectors have now adopted large-scale directed energy deposition (DED) process with either powder or wire as feedstock materials to expedite the manufacturing process of large-scale metallic components. To meet the rising demand of fast-prototyping, wire-arc additively manufacturing (WAAM) stands in its own domain among a variety of AM techniques owing to its high rate of deposition. In this work, we have chosen and exploited the WAAM process to manufacture stainless steels. The achieved material properties were obtained by unique microstructure design via the control of WAAM processing parameters.
4:15 PM
High-Throughput, Force-Based Measurements of Residual Stress and Comparison to Numerical Predictions: Kyle Johnson1; Dale Cillessen1; 1Sandia National Laboratories
Accurate simulation of residual stress in Additive Manufacturing (AM) is necessary to properly optimize processing conditions and predict part performance in subsequent environments. Development of predictive models requires experimental measurement of residual stress for calibration and validation. These measurements typically consist of either diffraction- or relaxation-based methods. Diffraction-based methods can offer high resolution and accuracy at high cost. Relaxation-based methods offer lower cost, though this can come at the expense of resolution. Both classes of methods depend on a measure of strain or displacement. Here we present a novel method that offers high throughput and a direct force measurement caused by residual stress. The method is demonstrated on a range of AM Kovar builds with varying process parameters. The resulting force measurements are then directly compared to numerical predictions. The method is also compared to a traditional relaxation-based method on the same part, and advantages and limitations are discussed.
4:35 PM
Multiscale Characterisation and Evaluation of the Effect of Recycling on Powder and Build Parts Performance: Rotimi Oluleke1; John Duffy2; Scott Speakman2; 1Carpenter Additive; 2Malvern Panalytical Ltd
Powder recycling in additive manufacturing is often seen as good industrial practice, offering both economic and environmental benefits because of waste reduction. It enables excess powder to be reused for subsequent build, once mixed with the virgin or as-received powder. However, as more parts are made and more recovered powder is added, the ratio of virgin to recovered powder may change. It is therefore important to track these changes to ensure that the resulting parts made from recovered powders still perform identically to the parts made from virgin powder.In this study both virgin and recovered powder and their corresponding build parts are characterized as a function of build number using a range of conventional characterization techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD) and supplemented with mechanical testing. These have shown to have the necessary sensitivity to detect minor variations of consequence in parts and recovered powder.
4:55 PM
Numerical Investigation of Gas-driven Powder Motion in Laser Powder Bed Fusion: Fangzhou Li1; Wenda Tan1; 1The University of Michigan
In the laser powder fusion process, the powder spattering contributes to the formation of defects such as lack-of-fusion and surface irregularity. The powder-gas interaction that triggers such spattering can be inferred from experimental observations but has not been well quantified. In this work, we use a computational physics model to investigate the powder motion. The effects of various processing conditions on the laser-induced gas flow, powder-gas interaction forces, and the resultant powder motion will be investigated systematically.