Keynote papers receive an extended oral presentation slot in the programme and will go to be published in the journal Powder Metallurgy who sponsors the award.

The EPMA Keynote Papers for World PM2023 are:

Monday 02 October 2022

Insights On The Microstructural Characteristics Of WC-Co-Ru Cemented Carbides

Dr Raquel de Oro Calderon (TU Wien, Austria) 

Abstract: WC-Co cemented carbides alloyed with Ru are relevant for the hardmetal industry in spite of their high cost. These alloys are used in applications requiring very demanding thermal properties and good performance in aggressive and abrasive media, and for some applications, it is difficult to find an alternative material that could offer a similar performance. This paper will provide important insights on phase formation, solubilities and microstructural characteristics of WC-Co-Ru alloys with different carbon contents that can shed some light on the mechanisms that affect the mechanical performance of these materials.

Time: 14:00 – 15:30

Session: Hard Metals/WC-Based Hardmetals

Room: 3.1

Tuesday 03 October 2023

Effect Of Process Parameters And Heat Treatments On Non-equiatomic CoCrFeNiMoxAly HEAs Manufactured By PBF-LB|M Via In-situ Alloying

Mr S Venkatesh Kumaran (IMDEA Materials, Spain)

Abstract: Manufacturing high entropy alloys (HEAs) using powder bed fusion-laser beam/Metal (PBF-LB/M) enables their production with minimal elemental segregation due to its inherently fast cooling rates resulting in excellent properties. So far, HEAs have been fabricated with fully pre-alloyed gas-atomized powders which makes it expensive and slower to explore new alloy compositions. In this work, for the first time, instead of pre-alloying, blended powders of CoCrF75, Ni625, Invar36, and pure Al powders were used as feedstock to develop a CoCrFeNiMoxAly HEA which consists of FCC phase in the metastable state. The process was successfully optimized, achieving relative densities greater than 99.8%. Moreover, annealing at various temperatures and times is performed to study its effect on precipitating new phases such as BCC, sigma, and μ. This method of mixing powders for PBF-LB/M enables rapid exploration of new HEAs and this work is expected to contribute to its successful application in the future.

Time: 08:30 – 10:00

Session: AM Beam Based Technologies – AM High Entropy Alloys

Room: 3.2

The Reporting Of Research On Gas Atomisation

Dipl-Ing Dirk Aderhold (Atomising Systems Ltd, United Kingdom)

Abstract: The ever-increasing interest in additive manufacturing (both binder jetting and LPBF) has led to a renewed interest in gas atomising research across the globe. As this is being done by workers with different atomising equipment, the opportunity arises to test both theoretical and empirical correlations on a variety of designs.  This paper reviews some relevant literature and sets out some basic equations and the relevant parameters that should ideally figure in all reports on gas atomisation tests.  A methodology is proposed to standardise reporting of date, e.g. mass-median, standard deviation, graphical methods and operating parameters to allow some benchmarking by gas atomiser operators and allow improvements to be clearly identified.

Remaining unanswered questions on gas atomisation will be discussed, which would surely benefit from more comprehensive publication, in particular the question of the importance of gas pressure in determining “efficiency” of atomisation, and how “efficiency” might be assessed and compared.

Time: 14:00 – 15:30

Session: Powder Production – Fundamentals of Gas Atomization

Room: 3.2

Wednesday 04 October 2023

Flash Spark Plasma Sintering Of Nd-Fe-B Magnets With Tailored Anisotropic Magnetic Properties

Prof Dr Martin Bram (Forschungszentrum Jülich, Germany)

Abstract: Flash spark plasma sintering (Flash SPS) is an attractive alternative method for the processing of Nd-Fe-B magnets with anisotropic magnetic properties. Therefore, a load is applied on a pre-compacted sample. Then, a well-defined power pulse is applied followed by deformation and densification of the sample in seconds. Compared to established processing of anisotropic magnets via hot pressing with subsequent die-upsetting, Flash SPS introduces the possibility of electroplasticity as an additional deformation mechanism. This mechanism has the potential to improve the magnetic properties through the fine-tuning of the microstructure. Our results reveal that suitable pre-heating of the sample before applying the power pulse plays a crucial role for tailoring grain size and grain aspect ratio, both being the key for well-pronounced anisotropic magnetic properties. For better understanding of the relationship between Flash SPS parameters, microstructure and resulting magnetic properties, in the present work a systematic parameter study has been done.

Time: 08:30 – 10:00

Session: Hard Magnetic Materials

Room: 3.1

Nitrogen Alloyed Austenitic Ni-free Stainless Steel For Additive Manufacturing

Mr Atte Antikainen (VTT, Finland)

Abstract: Nitrogen alloyed Austenitic Nickel-free Stainless Steel (ANFSS) is one of the most promising group of materials for consumer and health care products. They can be used to substitute not only conventional AISI 316L, but also Titanium and Co-Cr alloys. Previously the utilization of Nitrogen alloyed materials has been limited due to high work hardening rate. Recent developments in powder metallurgy, e.g. Additive Manufacturing (AM), are offering economically feasible net shape manufacturing routes to go around machining related problems. In the present study a viable processing route for ANFSS powder is introduced. It includes gas atomization and AM of test specimens by laser- and sinter-based methods. Special attention is paid on controlling the nitrogen content in different processing steps. The results show that by proper selection of processing parameters, the nitrogen content can be kept in desired level, thereby controlling the mechanical properties of ANFSS alloys.

Time: 11:00 – 12:30

Session: Ferrous Materials – Nitrogen Alloyed Steels

Room: 3.2

Cracking Susceptibility Assessment Of L-PBF CM247LC Alloy Based On Composition And Process Parameter Modifications

Dr Ane Miren Mancisidor (LORTEK, Spain)

Abstract: CM247LC alloy is a precipitation strengthened nickel-based superalloy commonly used in aeronautic sector due to its outstanding mechanical, oxidation, creep and wear properties at room and at high temperatures. However, there is a big challenge in obtaining a crack free material during PBF-LB/M processing. High contents of Al and Ti induce cracking. Four batches of CM247LC powders with different compositions were analysed and processed by PBF-LB/M. In this study, different approaches were employed to mitigate crack susceptibility of the alloy, namely, alloy modification, process modification and post-processing by HIP. The influence of the elements on cracking was assessed as well as the process parameters modification, including modification of the laser scanning strategies. Microstructure before and after post-processing, namely heat treatments and HIPping, was evaluated and cracking mechanism was studied in the light of microstructural observations..

Time: 14:00 – 15:30

Session: AM Beam Based Technologies – Non Weldable AM Materials

Room: 5.2