PowderMet          AMPM          Special Interest          TNT Presentations

049 - Advancing Resistance-Based Sintering: Rapid Metal Consolidation with Enhanced Efficiency and Precision
Olga Eliseeva, EWI

Resistance-Based Sintering (RBS) is an efficient method for consolidating metals such as aluminum, copper alloys, steels, and titanium. The process applies current and pressure directly to metal powders, generating heat to enable rapid sintering. The process is similar to spark plasma sintering (SPS) but RBS employs higher current densities and direct current application. This significantly reducing consolidation times to just 150 milliseconds to 4 seconds, while also eliminating the need for atmospheric shielding. RBS enables the production of complex metal matrix composites (MMC) and near-net-shape components, achieving a 97% reduction in energy consumption compared to traditional press-and-sinter techniques. Previous models of RBS have treated particle-to-particle contacts during sintering as a series of projection welds, leading to solidification. This work builds upon that foundation by focusing on the localized heating within the billets, providing detailed mapping of the melting and solidification physics throughout the entire welding cycle.

058 - Distinguishing Entrainment and Entrapment in Particle-Laden Flows: A Statistical and Machine Learning Approach
Md Akibul Islam, University of Maine

Entrainment is a well-known process for mineral, sand, silt, and gravel processing, handling airborne particles compared to entrapment processes, though these processes are conflated in material systems. In this paper, we tried to distinguish between the entrainment and entrapment processes by analyzing various statistical distributions such as Weibull, normal, and lognormal distributions. To make a clear distinction between entrainment and entrapment, the Self-Organizing Maps (SOM) were analyzed with a focus on mean quantization error, overall mean distance, agglomeration, and surface coverage. More uniform particle distribution is obtained from the entrainment process, whereas the entrapment process exhibits a higher level of particle clustering and agglomeration. The results of SOM parameters further support the distinctions, in that it represents lower mean quantization errors and more consistent surface coverage for the entrapment as compared to the entrainment process. These findings provide new insights into the mechanisms of particle behavior in complex suspensions and have implications for optimizing material properties and improving industrial processes. This work points out the importance of both the entrainment and entrapment processes in the design and analysis involved with particulate systems. By giving a clear distinction of these processes, this research aids in the development of more efficient and effective ways of controlling particle behavior in different applications and ultimately results in improved performance and stability of particulate systems.

071 - Rare Earth Magnets
Kalathur Narasimhan, FAPMI, P2P Technologies

Rare earth permanent magnets for the past 40 years dominated higher performance magnetic devices market. Raw material resource concentration in certain geographical areas threaten the market stability for rare earth permanent magnets. Material scientists have an opportunity to come through again. Use of elements such as nitrogen, nanostructure materials, and metastable materials are being explored. Electric vehicles are coming on stream as demand for greener energy grows. The motors require higher energy magnets and the need for more powerful magnets continues. This presentation reviews the developments and the challenges facing these alternate materials.

067 - Evaluation of AM Technologies in MIM Applications
Joseph Tunick Strauss, FAPMI, HJE Company, Inc.

Prior studies compared MIM’d parts to binder jet printed parts with respect to tolerance and surface finish. This study is expanded to include other sinter-based AM technologies including vat photopolymerization and material jetting. Process mechanisms and limitations will be discussed.

060 - Thermal Sprayed Ultrahard Alloy Powders for Improved Stamping Die Surfaces: Characterization of Parameter Effects
Iver Eric Anderson, FAPMI, Ames National Laboratory

Greater manufacturing efficiency of lightweight automotive panels and parts could be achieved by better stamping processes, especially for aluminum alloy sheet. Lighter vehicles from these lightweight auto body panels will reduce greenhouse gas emissions both by improving gas mileage for ICE vehicles and by extending driving range for electric vehicles. Wear resistant die claddings are being developed from gas atomized powders of new ultrahard refractory high-entropy alloys (RHEA) developed by Ames and Sandia National Labs to greatly improve the service life of automotive sheet metal stamping die inserts and minimize die lubricants. Our collaborations with Ford involve 2 types of wear test specimens that are coated (100µm thick) by high velocity oxy-fuel (O2/H2) spraying on flat contact surfaces by TST Fisher Barton. Results of block-on-ring and sliding wear tests with microstructure analysis are reported, comparing “hot” and “cold” parameter settings.

052 - Environmentally-Friendly Batch Type Boilerless Steam Treatment Process for PM Parts
Ravindra Kumar Malhotra, Malhotra Engineers

Batch Steam Treatment furnaces are one of the oldest equipment's designs serving Powder Metallurgy plants for a long time next to Iron Sintering furnaces. A dedicated steam boiler compliments the working of a Batch Steam Treatment furnace as its steam source. Even today, some of the steam treated parts are preferred to be processed in a batch furnace for higher oxide layer deposition. This is true especially for parts needing pore sealing to be leak proof. Batch Steam Treatment cycles practically complete within a working shift of eight hours. Batch Steam Treatment Process was analyzed and converted to Continuous Steam Treatment Process for bulk production. Continuous furnaces eased the bulk steam treatment parts processing as an important secondary PM operation after the sintering or machining of PM parts. Overtime Boilerless Continuous Steam Treatment furnaces were introduced to serve PM plants to make them safer and more reliable. A relook at Batch Steam Treatment Process as a boilerless environmentally friendly design would serve the PM Industry well for their important secondary process of Steam Oxidation. An improved version of Batch Steam Treatment furnace using less water and effective oxidation control with higher turnaround batches per day will help smaller plants boost productivity without looking at costly Continuous Steam Treatment furnaces. Additional features like selective hydrogen venting and removal of recirculation fan can speed up the steam oxidation process. Recycling condensate water can also be a new feature of this furnace.

098 - Consolidation Modeling of a Complex AM+PM HIP Part
Jason Mayeur, Oak Ridge National Laboratory

Fabricating components via PM HIP is a well-established process capable of producing high quality near net shaped parts with excellent material properties. The process has been widely adopted by the offshore oil and gas industry and is increasingly being explored as an alternative process to make large parts for other energy sectors (e.g., nuclear, hydroelectric) to diversify manufacturing supply chains. One of the primary bottlenecks for producing PM HIP parts is the design and fabrication of the capsule. HIP capsules are typically fabricated through hand-working and welding sheet metal to produce the desired capsule geometry, which can be laborious for complex geometries. To this end, there is interest in exploring the feasibility of fabricating HIP capsules via additive and/or hybrid manufacturing processes, which has the potential to drastically reduce capsule fabrication time and increase design flexibility. An additional limiting factor is the lack of commercially available PM HIP process modeling tools capable of accurately predicting component shrinkage during HIPing, which is required for proper capsule design. In this study, we present an implementation of a PM HIP process model into a commercial finite element code, and predict the consolidation behavior of a t-valve produced with a laser wire DED AM capsule. Model predictions are compared against the experimentally measured post-HIP geometry.

099 - Effects of Embedded Lattice on the Deformation and Properties of AM HIP Containers
Fred List, Oak Ridge National Laboratory

Hot isostatic pressing (HIP) of powder-filled, additively manufactured (AM) cans involves complex mechanical deformation that disrupts the pathway to near-net-shape fabrication. Efforts have been undertaken to determine and understand the impact of printed lattice structures within simple cylindrical AM cans on deformation, microstructure, and mechanical properties. Diamond and rhombic-dodecahedral lattices with 4-mm and 8-mm node spacings have been printed to fill the entire internal volumes of cylindrical, 316L stainless steel, AM cans. These lattice-filled cans, as well as AM cans without lattice, have been filled with 316L stainless steel powder and HIP processed using identical cycles. By direct comparison of HIP AM cans with and without lattice, the contributions of the lattice have been identified and will be discussed. Understanding these contributions leads to strategies for tailoring HIP deformation by selectively filling only portions of the HIP can with lattice. These strategies will also be discussed in this presentation.

011 - Alloy Design of Steels for 3D Printing by LPBF
S. Sundar Sriram, Sundram Fastners Limited

Defect free 3D printing of medium and high carbon alloy steels using LPBF is still a challenge. Alloy design of steels for printing using concepts of carbon equivalent (CE), hardenability in terms of ideal diameter (DI), martensitic start temperature (Ms) and particle size and shape is attempted to arrive at conditions which can predict the printability of high alloy steels.

015 - Tool Steels in Laser Additive Manufacturing: Leveraging Machine Learning to Mitigate Cracking
Justin Plante, Laval University

Additive Manufacturing by Laser Powder-Bed Fusion (LPBF) presents significant advantages in the design and repair of tooling components. However, the availability of suitable tool steel powders is still limited. Most commercially available powders closely resemble their wrought counterparts in chemical composition, which are not tailored for the rapid solidification and thermal cycling characteristics inherent to LPBF. This misalignment can lead to cracking, negatively impacting mechanical properties. Recent advancements in machine learning (ML) offer innovative solutions to these challenges. In the realm of alloy development for LPBF, ML can enhance the analysis of metallographic images by automating the detection of critical defects, such as cracks, pores, and shrinkage porosities—tasks that are often tedious when performed manually. This study investigates water-atomized tool steel powders for their applicability in LPBF, emphasizing how chemical composition influences cracking susceptibility. By leveraging ML, we analyze metallographic data to identify composition-related factors that affect cracking behavior. This data-driven approach provides a robust framework for improving the reliability and performance of LPBF components, making additive manufacturing a more viable and appealing option for industrial applications.

006 - 3D Printed Powder Compaction Tools
S. Sundar Sriram, Sundram Fastners Limited

High carbon alloyed ferrous powders and Laser powder bed fusion methods have been developed for making powder compaction tools primarily punches for compacting powder metal parts. These tools are printed to near theoretical densities and are crack free despite the high carbon and alloy content. These tools are used for quick tool development for new parts as well as serial production. The additive nature of the manufacturing of tools ensures RM yields greater than 90%. Parts which are compacted at compaction pressures ranging from 300 MPa and 700 MPa have been found suitable for being compacted using printed PM punches.

509 - Sample Preparation and Revealing the Microstructure
Thomas Murphy, FAPMI, Hoeganaes Corporation

To perform an accurate metallographic analysis on AM or PM samples, several preliminary conditions must be met. The first step in the process is to realize the intended outcome of the analysis, then develop a process to attain this goal. Following this concept stage, the correct sample must be selected and removed from a larger part of volume of powder, it is probably encapsulated in a structurally sound mount, then ground and polished to reach the true microstructure. Many analyses can be performed on the as-polished surface, however the different components in the microstructure are usually revealed using chemical etchants, tint etchants (stains), and utilizing specialized microscopy techniques. Each step in the process must be accomplished correctly to ensure an accurate analysis.

510 - Practical Examples of Metallographic Testing of Sinter-Based AM Materials
Thomas Murphy, FAPMI, Hoeganaes Corporation

Revealing the microstructure correctly is an essential element in performing a meaningful metallographic analysis. Once this is accomplished, various examinations can be performed that help explain the history of a part, its behavior during processing and in service, cause for failure, and countless other examples. This presentation is comprised of several metallographic analyses made on sinter-based AM and PM parts and powders.

511 - Practical Examples of Metallographic Testing of LPBF and Melt-Based AM Materials
Thomas Murphy, FAPMI, Hoeganaes Corporation

Revealing the microstructure correctly is an essential element in performing a meaningful metallographic analysis. Once this is accomplished, various examinations can be performed that help explain the history of a part, its behavior during processing and in service, cause for failure, and countless other examples. This presentation is comprised of several metallographic analyses made on melt-based AM parts and powders.