PowderMet          AMPM          Special Interest

107 - A Comparison of the Mechanical Properties and Production of Powder Metallurgy Components Made with New Lubricants and Sintered Using Two Different Sintering Approaches
Scot Coble, Abbott Furnace Company

New lubricants are seeing regular use in the compaction of higher density powder metallurgy components.  Although it is seeing more and more use, little work has been done to review the impact that this lubricant has on the sintering process. Here, the effect of this lubricant as a function of compact density, lubricant amount, and sintering method will be reviewed.  A look at the impact on the physical properties, production rate, and quality of the final compacts will be demonstrated.

036 - Debinding, Sintering & Hardening in Vacuum Furnace Systems for AM/PM Parts
Vincent Esteve, ECM USA, Inc.

What does it take to bring PM and Additive Manufactured parts into large scale production with a cost efficient and time saving process? Ideally, one vacuum furnace system can achieve adaptable production capacity, reduce cycle time, and quickly switch part designs and materials for all AM/PM parts.   We will discuss how one vacuum furnace system can be used to perform debinding, sintering, hardening (and more processes likes carburizing and carbonitriding) in the same chamber with an all-inclusive cycle to save time, energy and costs for AM/PM part manufacturers.  In this presentation, we will present results from a metallurgical point of view regarding materials used in a fully integrated furnace solution, and will conclude with our perspective of what the future could be for PM parts in the industry.

068 - Performance of Converging-Diverging Nozzles for Close-Coupled Gas Atomization
Franz Hernandez, Ames Laboratory

For the powder production industry, yields, powder quality and production rate are vital. The effect of gas-to-metal ratio and geometry on the efficiency of the atomizer has long been debated.  Here, we will compare traditional designs with converging-diverging nozzles and discuss the benefits and trade-offs. The study is performed numerically using a compressible flow model.

095 - Sintering Process Optimization with Industry 4.0 Technologies
Liang He

Continuous sintering of metal parts under a Nitrogen/Hydrogen atmosphere is one of the most complicated heat treatment processes. Although the industry has established standard processing methods, the technical challenges still remain to minimize part defects, rework, and the excessive use of energy. A cloud-based process optimization system dedicated to sintering has been developed. This Industry 4.0 tool enables recording and analysis of the production parameters, linked to operational results, facilitating process optimization and product quality improvement. Integrated with thermodynamic calculations, field experience, and documentation features, the tool provides process engineers with extended capabilities to manage the production, and support the process troubleshooting. In this article, results of our recent research and development work on this project will be presented and discussed. 

040 - Model-Based Decision Making in the Automotive Industry and Its Impact on the Powder Metallurgy Industry
Ian Donaldson, FAPMI, GKN Sinter Metals

There has been a rapid adoption in industry of model-based engineering, which is a formalized approach to engineering that uses models as a fundamental part of the conceptualization, analysis, implementation, and validation associated with complex systems.  In automotive, technical baselines have been established to facilitate understanding of the product performance and aid decision making through scenario planning.  The objectives are to reduce costs, reduce time and detect early defects.  A significant part of this is the use of material databases to reduce physical testing needs.  The requirements for the databases are to have extensive accurate static and dynamic mechanical property data.  This negatively impacts the powder metallurgy (PM) industries because there are less data available than wrought or cast materials.  This paper discusses the potential reduced opportunities for PM sourcing, steps needed to mitigate exclusion with examples of property requirements and use of modeling for decision making.  

081 - Improvement in Properties and Elimination of Microcracking in LPBF Printed Nickel Alloys Through Control of Nucleation and Dispersion Strengthening
Jeremy Iten, Indiana University - Elementum 3Ds

Nickel alloys such as UNS N06230 a nickel-chromium-tungsten-molybdenum alloy are susceptible to microcracking when printed by laser powder bed fusion additive manufacturing. Understanding and control of solidification has enabled elimination of microcracking in the modified H230 alloy. Similar techniques have utilized to demonstrate significant property improvement in other nickel alloys including enhanced Ni - 625 and 718, C276, and Ni-080 . An integrated computational materials engineering (ICME) framework was developed and utilized to predict alloy crack susceptibility and facilitate design of robust alloys for additive manufacturing. The model was experimentally validated by printing and characterizing nickel alloys based on standard and modified compositions.

091 - Boron Modified Silica Nano-Lubricant as a Powder Rheology Modifier and Sintering Aid for AISI 420 
Arun Chattopadhyay, Uniformity Labs

The use of nanolubricants in powder metallurgy is a major advancement for various additive manufacturing processes. The use of nanoadditives in the form of nanoparticles is highly efficient due to their high surface area and ability to adhere specifically on metal particles smaller than 10 micron. This study is aimed to investigate the effect of adding boron-modified SiO2 nano-powder on the sintering properties of AISI 420 stainless steel (SS). The final density, dimensional changes, and mechanical properties have been studied for the samples prepared under a series of sintering conditions. 

084 - Advances in Printability of Aluminium AM Powders: Solution to Hot Tearing in LBPF Printing of AM Structural Parts
Jason Ting, Elementum 3D

Aluminium 2024 and 6061 grades are frequently chosen as a cost-effective structural material for their high strength to weight ratio in many aerospace applications.   However, aluminium AM parts built from the L-PBF process using conventional aluminium 2024 and 6061 compositions tend to develop hot tearing defects that compromise their strengths and diminishes their applications.    A reactive additive manufacturing process, known as RAM, was developed whereby a nucleation mechanism was introduced to the aluminium powder.  This created a predictable and a controllable grain refinement to the AM part microstructure.  As a result, the hot tearing defects were eliminated from the AM parts. This patented technology has enabled to one to print aluminium grade powders from previously unprintable conventional Al grades. In addition, the new printable Al 2024 parts have better mechanical properties compared to their wrought Al 2024 counterpart.

141 - Processing Titanium Nitride Directly From Plasma Synthesized Powders Using Electron Beam Powder Bed Fusion
Francisco Medina, University of Texas, El Paso

The unprecedented demand for new extreme materials has resulted in a rapid expansion of additive manufacturing (AM) based fabrication methods to develop titanium-based refractory metal alloys and compounds for use in harsh environments, especially, at high temperatures and pressures. This class of materials with high melting points, high-temperature strengths, excellent creep, wear, and ablation resistance is suitable for a broad range of structural and coating applications in the transportation, electronics, and other industries. Recent advances in electron powder bed fusion (E-PBF) have enabled the development of the protocols for processing bulk titanium nitride. Excellent biocompatibility of titanium nitride makes this material attractive for use as implant materials potentially replacing CoCr or Ti6Al4V alloys. Herein, we will describe the conditions developed for a plasma synthesized titanium nitride powder that has been consolidated into dense bulk products. Metal nitrides are refractory compounds formed by the bonding between nitrogen and transition elements, such as titanium.  Using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, electron backscatter diffraction analyses as well as microhardness measurements we will delineate differences in phase content, morphology, and texture between the precursor feedstock powder and the 3D printed solids. We will also provide an account of the microstructural evolution during the 3D Printing process.

025 - Impact of Particle Size on Rheology and Mass Flow During Directed Energy Deposition Additive Manufacturing
Todd Palmer, Center for Innovative Sintered Products

Significant variations in mass flow rates during processing were identified for a lean (UNS S32101), standard (UNS S32205), and super (UNS S32750) duplex stainless steel powders using directed energy deposition additive manufacturing. Across three different directed energy deposition systems, the lean grade consistently displayed the lowest mass flow rates which impacted final build geometry.  Although traditional powder characterization methods were unable to identify differences between the three powders, advanced powder and rheological characterization tools linked particle characteristics and rheological properties to powder flow and performance. The lean grade was discovered to have a particle size distribution shifted to slightly larger sizes, which resulted in a higher fraction of larger particles with higher masses that resisted motion and increased particle-particle and particle-gas flow resistance. This increased flow resistance was captured through cohesion strength and fluidization measurements during rheological testing.  

009 - Methodologies for Analysis of Powder Contamination During Binder Jetting
Mathieu Brochu, McGill University

In additive manufacturing processes, changes to the powder due to recycling can lead to degradation that may or may not be detected by traditional powder characterization techniques. Specific to binder jetting, the inherent poor flowability of powders ascribed to their fine particle size distribution, makes the traditional powder characterisation methods are less efficient to detect the presence of surface contaminant and/or the level of degradation. In this presentation, a new method for quantifying powder contamination is proposed and the results will be compared with those obtained from traditional powder characterisation techniques. The method will be demonstrated using low alloy steel and copper powders.

005 - Developing Sintering Parameters for Binder-Jet Printed H-13
James Sears, FAPMI, Amaero Additive Manufacturing

H13, also referred to as DIN 1.2344 or X40CrMoV5-1 steel, is a hot work steel containing up to 0.4 wt% C and is strengthened by martensite and carbides. It has excellent hot toughness, wear resistance and hardenability thereby warranting its use in both hot and cold work applications such as die casting, injection molding, extrusion and forging. H13 steel dies are currently fabricated via a combination of CNC milling and EDM that have limited capability to produce certain die geometries and internal features such as conformal cooling channels. Additive manufacturing offers a solution to circumvent this limitation. However, H-13 poses a challenge for LPBF technologies due cracking cause by to the solid-state martensitic transformation. Binder-jet printing (BJP) avoids this issue since the sintering is performed at uniform temperatures and much slower cooling rates. Sintering parameters considered were furnace atmospheres, hold times and temperatures to produce near full density. Carbon chemistry control provided critical for this process.

204 - Printing CuO Paste with Laser Processing: A Novel Approach to Printed/Flexible Electronics
Sihan Zhang, University of Louisville

Printed electronics has drawn research interest due to its flexibility, cost-effectiveness, and eco-friendliness, when compared to its competitors in traditional methods. This research combines 3D printing CuO paste with laser processing to fabricate conductive patterns on various substrates. Commercially available CuO paste was printed with a custom-made auger print head and followed by 500 mW laser processing. The reduction of CuO to Cu was achieved by laser processing, which does not require inert or reductive gas atmosphere. The CuO paste was characterized with XRD, TGA-DSC and UV-vis spectrometer. The conductive Cu lines were characterized with optical microscope and the resistivity was measured using a probe station. Both the print head and the laser module are compact and can be mounted on a multi-tool 3D printer. The overarching goal is to develop a flexible, rapid, and cost-effective method for printed electronics.        

124 - 3D Printing of Non-Ferrous Alloys via Metal Fused Filament Fabrication (MF3)
Kameswara Ajjarapu, University of Lousiville

Fused Filament Fabrication (FFF) is a primitive additive manufacturing (AM) technique to fabricate intricate polymeric parts in a quick and cost-effective manner. Powder fused filament fabrication (PF3) 3D printing process utilizes powder-filled polymer filaments and a combined Fused filament fabrication (FFF) and sintering processes to fabricate complex metallic and ceramic structures. Powder filled polymeric feedstocks and filaments were prepared, which were subsequently 3D printed. Non-ferrous metallic alloy green parts were sintered and characterized to understand the physical and mechanical properties of the final part. The current work aims to address critical knowledge gaps to enable a seamless transition from Fused Filament Fabrication (FFF) to Metal Fused Filament Fabrication (MF3) by utilizing fundamental concepts of Powder Metallurgy (PM) and Metal Injection Molding (MIM). Additionally, process maps and models were inculcated to predict powder-polymer material properties critical to perform process simulations using platforms.

515 - Soft Magnetic Composite Opportunities in Future E-Mobility
Fatmeh Bonanno, North American Höganäs Co.

Alvier Mechatronics GmbH is an engineering company where one focus area is exploring the advantages of SMC materials in automotive and industrial applications. In this presentation, the use of SMC in several application areas such as automotive traction, smaller auxiliary high torque motors, inductors for DC/DC converters will be shown highlighting the value added as well as the necessary enablers: using the full potential of the material properties. 

The past decade has seen significant development in the field of Soft Magnetic Composite (SMC) materials and their application in electrical machines and passive components (e.g. inductors, actuators). One part of this can be attributed to their isotropic thermal and magnetic properties, allowing for relatively complex structures to support magnetic flux. Another part is their high saturation flux density and inherent ability to supress high frequency eddy-current iron losses due to the small, inorganically insulated iron particles and high component bulk resistivity.

503 - Powder Metallurgy—Electrification & SMC
Ahmad Khan, GKN Sinter Metals

This presentation will highlight how powder metallurgy and SMC components can be used in innovative motor technology. Multiple applications will be highlighted and discussed, as well as the benefit for the overall industry. This will spark innovation within the powder metallurgy industry and show the new business possibilities across multiple other industries. Axial and Transversal Flux Motors to be presented.

509 - Effect of SMC Properties on EV Motor Efficiency
Fabrice Bernier, National Research Council Canada

The impact of varying different SMC properties on the efficiency of various EV motor designs was evaluated using a FEA magnetic simulation software. This approach allows to rapidly identify the SMC properties that are most critical for a given design, as opposed to those which have only a minor impact thus focusing the R&D development effort to SMC material possessing the desired properties combination. In this work, this approach was adopted to test the performance of three different virtual SMC materials in three different electric machines designs (radial, axial and transverse flux permanent magnet). The evaluated materials had respectively a low permeability and low losses (material A), medium permeability and medium losses (material B) and high permeability and higher losses (material C). The simulation results show that an SMC material with balanced properties achieved the highest efficiency and best overall performance for all three considered motor designs.