World PM2022 Proceedings

Authors:

Agathe Deborde (IRT M2P, France), Aurélie Franceschini (IRT M2P, France), Stéphane Hans (Aubert&Duval, France)

Abstract:

Powder metallurgy is used in various industries such as aerospace, medical, defence, etc. For high cleanliness materials, metal powders can be produced using the EIGA process (Electrode Induction melting Gas Atomization). The EIGA process involves the crucible-free melting of an ingot followed by atomization using high-pressure argon. A full-scale EIGA is installed at MetaFensch|IRT M2P for R&D purposes (alloy development, numerical simulation, upscaling, etc.).Process parameters such as electrode size and gas parameters have a predominant influence on powder size and yields. On the other hand, chemical composition of the alloy and the associated thermophysical properties have a significant impact on the atomization process, and therefore on the quality of the powders. To better understand the effect of the composition, several alloys were selected (Ti64, titanium aluminide, nickel-based alloys, etc.) and atomized using the EIGA process. The properties of the powders, especially particle size distribution and morphology, are compared.

DOI:

https://doi.org/10.59499/WP225372000

Authors:

Tomi Lindroos (VTT, Finland), Timo Kinos (VTT, Finland), Kimmo Kaunisto (VTT, Finland), Tuomas Riipinen (VTT, Finland), Sini Metsä-Kortelainen (VTT, Finland), Aino Manninen (VTT, Finland), Jenni Pippuri-Mäkeläinen (VTT, Finland)

Abstract:

Electrification of the world has significantly increased the demand for novel high performance electromechanical components. Powder Metallurgy and especially Additive Manufacturing are seen as enablers to produce components based on novel soft magnetic materials with performance and designs unattainable with conventional manufacturing. Fe-Si-X soft magnetic materials were studied by focusing to tailor material to Laser Powder Bed Fusion (L-PBF) processing. Effect of different alloying elements on magnetic, electrical and mechanical properties were studied based on simulations and experiments. The focus was paid on increasing the understanding of segregation occurring at high cooling rates and how it could be utilized in controlling electrical resistivity and consequently the mitigation of eddy current losses. Gas atomized powder corresponding the most promising alloy composition was produced and further, test components were manufactured by L-PBF accompanied by appropriate heat treatments. The results of resistivity and magnetic measurements are promising when compared against conventional Fe-Si alloy.

DOI:

https://doi.org/10.59499/WP225371873

Authors:

Tsukasa Shirafuji (Kobe Steel, Ltd., Japan), Yuji Taniguchi (Kobe Steel, Ltd., Japan)

Abstract:

The fatigue strength of sintered steel is normally lower than that of conventional low-alloyed steel, such as JIS SCr420 and JIS SCM415 and so on,The fatigue strength of sintered steel is normally lower than that of conventional low-alloyed steel, such as JIS SCr420 and JIS SCM415 and so on, due to the porosities inside the material. However, it has been reported that tooth bending fatigue strength of sintered gears manufactured from 46F4H (0.5Ni-1.0Mo Pre-alloyed Steel Powder) is improved by surface-rolling and that the fatigue strength is equal to or higher than that of the gear manufactured from the wrought steel. In this study, we found that the reason why surface-rolled sintered steel gears have high fatigue strength is caused by both a decrease in size of the initiation fatigue crack due to eliminate the porosities in the vicinity of surface of the gear, and high compressive residual stress.

DOI:

https://doi.org/10.59499/WP225364378

Authors:

Toshiko Osada (Tokyo Metropolitan University, Japan), Satoshi Kobayashi (Tokyo Metropolitan University, Japan), Yoshiyuki Kato (Kato Professional Engineer office, Japan), Kenji Yokoyama (ExOne, K.K., Japan)

Abstract:

Metal binder jet 3D printing is suitable for fabricating metal parts in small quantity and many varieties in a short period of time. Fine powders for metal injection molding are used for binder jet 3D printer. Powders need to flow during recoating to the powder bed, and also after that they need to show high density for enough strength of green parts for handling. In this study, powder characteristics for binder jet 3D printing is focused, and effect of distance between powders on the printing and sintering properties of metal binder jet 3D printing is clarified.

DOI:

https://doi.org/10.59499/WP225367565

Authors:

Miren Aristizabal (Ceit, Spain), Unai Galech (Ceit, Spain), Rafael Soler (ITP-Aero, Spain), Estibaliz Paños (ITP-Aero, Spain), Iñigo Iturriza (Ceit, Spain)

Abstract:

Gas atomised powder is widely used for HIP applications thanks to its beneficial properties in terms of flowability, compactability and few interstitials. Generally, a wide range of powder particle size is used in HIP to increase the powder efficiency, flow and compaction. While thin particles have to deal with oxygen pick up, wider powders suffer from entrapped gas porosity. These issues have been analysed and related with the properties of HIPped high temperature Ni superalloy. Characterisation have been carried out by mean of chemical analyses, microstructural analyses and mechanical tests. Results show that thin powders are prone to form PPBS and large powders have higher content of argon and both led to a ductility reduction. As a conclusion, gas atomised powder combining wide particle size range showed the best property compromise for Astroloy, making it suitable for the production of elevated temperature components for high-efficiency new jet engines.

DOI:

https://doi.org/10.59499/WP225371919

Authors:

Maheswaran Vattur Sundaram (Höganäs AB, Sweden), Fabien Currit (Höganäs AB, Sweden), Michael Andersson (Höganäs AB, Sweden), Dimitris Chasoglou (Höganäs AB, Sweden)

Abstract:

The properties and the performance of PM steels can be tailored and enhanced by performing an appropriate heat treatment process after sintering. Conventional gas carburising (CQT) is the most used process for PM steels, whereas for Cr-alloyed PM steels, casehardening by low-pressure carburising (LPC) is gaining interest due to its oxide free process and better control over case depth. Also, when combined with high-pressure gas quenching (GQ) it provides less distortion in the components. In this work, Cr-alloyed PM steel with and without Ni additions were evaluated after both the CQT and LPC heat treatment process. The mechanical properties and performances were evaluated, and the results obtained indicated a strong correlation between the obtained properties and resulting microstructures based on the alloying elements and optimised heat treatment process.

DOI:

https://doi.org/10.59499/WP225371514

Authors:

Quentin Saby (INSA Lyon, France), Jean-Yves Buffière (INSA Lyon, France), Thomas Joffre (CTIPC, France), Peter Vikner (Aubert&Duval, France), Xavier Boulnat (INSA Lyon, France)

Abstract:

Laser Powder Bed Fusion (LPBF) is an additive manufacturing process used to produce conformal cooling injection molds with complex internal channels, mainly using cobalt-rich 18Ni300 maraging steel. Yet, built parts with this steel powder still demand improved toughness and fatigue strength. As an alternative, this work describes the manufacturibility of two alternative cobalt-free martensitic stainless steels by LPBF. After a quantitative characterisation of the microstructure, defects and mechanical properties of as-built parts, different heat treatments were performed to (i) age the precipitation-hardenable low-carbon maraging steel (CX) or (ii) temper the high-carbon martensitic steel (PM420). The hardness, tensile strength, ductility, impact energy and fatigue behavior of as-built and treated parts were compared. The influence of the microstructure and the critical defects on the mechanical behavior is discussed, with an emphasis on the fatigue life. Finally, the manufacturing of complex injection molds using PM420 powder was assessed.

DOI:

https://doi.org/10.59499/WP225372159

Authors:

Matthew Dunstan (US Army Research Lab, USA), Brady Butler (US Army Research Lab, USA), Isaac Nault (US Army Research Lab, USA), James Paramore (US Army Research Lab, USA)

Abstract:

Cold Spray Additive Manufacturing (CSAM) is a solid-state additive technology where metal powders are accelerated through a converging-diverging Laval type nozzle using a pressurized carrier gas. These powders are then sprayed onto a substrate in the shape of the desired component and subsequently removed. As only low temperatures (<1000 °C) are used during CSAM, the strength of the component relies completely on particle deformation and interlocking as very little diffusional processing takes place in order to create metallurgical bonds. Post-spray heat treatments are often necessary in order for components to achieve mechanical properties similar to other additive techniques. In this work, the heat treatment process known as Thermohydrogen Reduction of Microstructure (THRM), which was initially developed for laser based additive manufacturing, is applied to Ti-6Al-4V components produced via CSAM. Its effect on density, microstructure, and tensile properties are examined.

DOI:

https://doi.org/10.59499/WP225365785

Authors:

Jean-Michel Missiaen (Univ. Grenoble Alpes, France), Mathilde Labonne (Univ. Grenoble Alpes, France), Olivier Lavigne (Hyperion Materials & Technologies, Spain), Luis Garcia (Hyperion Materials & Technologies, Spain)

Abstract:

Cemented carbides are widely used for cutting and drilling tools. They usually combine a WC hard carbide phase and a Co-based ductile binder. NbC-Ni materials are considered as a possible alternative, especially for wear applications. The advantageous economic situation for raw materials sourcing, their interesting mechanical properties and low density have raised a new interest for these materials. However, mechanical properties can be limited by the rapid grain growth during liquid phase sintering, as compared to WC-Co. Grain growth can be controlled by the addition of secondary carbides such as Mo2C. In this paper, a quantitative EBSD analysis of grain growth is performed for NbC-12vol%Ni materials sintered at 1360°C with controlled addition of Mo2C. The average grain size decreases continuously with Mo2C content. The results are discussed based on a more detailed interface characterization and on a previous model for the cooperative migration of phase boundaries and grain boundaries.

DOI:

https://doi.org/10.59499/WP225371483

Authors:

Thierry Baffie (CEA-LITEN, Univ.Grenoble Alpes, France), Guilhem Roux (CEA-LITEN, Univ.Grenoble Alpes, France), Mathieu Soulier (CEA-LITEN, Univ.Grenoble Alpes, France), Michel Pellat (CEA-LITEN, Univ.Grenoble Alpes, France), Claudia Salvan (CEA-LITEN, Univ.Grenoble Alpes, France), Claudie De Vernon (TOLECTRO SAS, France)

Abstract:

Recently, we showed that >99% dense CuCrZr parts can be produced by Laser Powder Bed Fusion (L-PBF) process using a large power range (270 to 480W) [1,2]. The as-built (AB) microstructure is anisotropic showing columnar grains aligned along building direction (BD). After a solution annealing and age hardening (SA+AH), solidification cells disappear and the dislocations density decrease, whereas partial recrystallization, twins and Cr nano-precipitates are observed. Even if the microstructure is not fully similar to wrought CuCrZr one, yield strengths are equivalent. This work aimed to develop further the process by: (i) evaluating the impact of incoming powders and lasing parameters on the AB microstructure, (ii) analyzing the microstructural effects of SA+AH and (iii) comparing the mechanical, thermal and electrical properties in both conditions for three powders.[1] C.Salvan et al., Proceedings EuroPM2019, Oct.13-17 2019[2] C.Salvan et al., Mat. Sci. & Eng. A 826 (2021) 141915

DOI:

https://doi.org/10.59499/WP225371437

Authors:

Anok Babu Nagaram (Chalmers University of Technology, Sweden), Eduard Hryha (Chalmers University of Technology, Sweden), Johannes Gårdstam (Quintus Technologies AB, Sweden), Maheswaran Vattur Sundaram (Höganäs AB, Sweden), Michael Andersson (Höganäs AB, Sweden), Zhuoer Chen (Chalmers University of Technology, Sweden)

Abstract:

In this study, compacts of Cr-prealloyed steel with admixed nickel and graphite, fabricated through cold isostatic pressing (CIP), were sintered in low vacuum at 1150 °C and at 1250 °C in a HIP furnace, followed by the capsule-free hot isostatic pressing (HIP) at 1150 °C in the same HIP furnace using argon at 100 MPa. Microstructures of these compacts sintered at 1250 °C revealed the complete closure of interconnected porosity, after which densification to full bulk density was achieved by final HIP stage. Hardness measurements and chemical analysis were also employed. Carbon as a reducing agent played a crucial part to reach very low oxygen content of 0.02% after sintering and capsule-free HIP. This study demonstrates the possibility of achieving full density in high performance powder metallurgy (PM) steels through novel approach of CIP and in-situ vacuum sintering in combination with capsule-free HIP using a two-stage densification process.

DOI:

https://doi.org/10.59499/WP225372077

Authors:

Peter Vikner (Aubert & Duval, France), Charlotte Mayer (Aubert & Duval, France), Corrado Muner (Texer design, Italy)

Abstract:

TS700 is a new precipitation hardening steel with high temperature resistance and excellent hot hardness developed for additive manufacturing of aluminium die casting tooling.TS700 parts were produced by L-PBF on a plate made in H11 tool steel treated at 45HRC. The interface between TS700 and H11 is investigated, as well as the microstructure evolution versus energy density (for different laser powers and scan speeds). The evolution of the microstructure with subsequent heat treatments is presented as well as some mechanical properties associated to the different microstructures obtained.

DOI:

https://doi.org/10.59499/WP225371564