Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels

Size, morphology and distribution of light and stiff, but inherently brittle particles are of critical importance for the property profile of high modulus steels. Powder atomisation can dramatically reduce the borides’ size to the nanoscale, but they typically coarsen substantially during annealing...

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Main Authors: M. Gathmann, D. Moisi, H. Springer
Format: Article
Language:English
Published: Elsevier 2024-11-01
Series:Materials & Design
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Online Access:http://www.sciencedirect.com/science/article/pii/S026412752400786X
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author M. Gathmann
D. Moisi
H. Springer
author_facet M. Gathmann
D. Moisi
H. Springer
author_sort M. Gathmann
collection DOAJ
description Size, morphology and distribution of light and stiff, but inherently brittle particles are of critical importance for the property profile of high modulus steels. Powder atomisation can dramatically reduce the borides’ size to the nanoscale, but they typically coarsen substantially during annealing or compaction via hot isostatic pressing. This study investigated the effect of compaction parameters, namely temperature, pressure and time on the coarsening mechanism, porosity evolution and resultant mechanical properties of atomised Fe-Cr-B powder. Increasing annealing temperature and time from 950 to 1150 °C, respectively, 30 min to 8 h, resulted in a non-linear boride radius growth from 76 nm in the atomised state to 1.9 µm. Hot isostatic pressing, with additional pressures up to 140 MPa, decreased the pore size from about 5 to 0.2 µm. An optimised hot isostatic pressing processing window was defined at 1050 °C and 140 MPa, combining sufficiently reduced defects with a limited particle radius, and yielded in 730 MPa tensile strength at more than 20 % tensile elongation. Powder-metallurgical synthesis of Fe-Cr-B achieved similar properties to casted and hot-rolled material, by avoiding component size scaling effects of casting. The underlying phenomena and optimisation of high modulus steel production via powder metallurgy are discussed.
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spelling doaj-art-3a615b232ded4b10a765e35b6c2b65e82025-08-20T02:30:42ZengElsevierMaterials & Design0264-12752024-11-0124711341110.1016/j.matdes.2024.113411Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steelsM. Gathmann0D. Moisi1H. Springer2Max Planck Institute for Sustainable Materials, Max-Planck-Strasse 1, 40237 Düsseldorf, Germany; Corresponding author.Rolls-Royce Germany Ltd & Co KG, Eschenweg 11, 15827 Blankenfelde-Mahlow, GermanyMax Planck Institute for Sustainable Materials, Max-Planck-Strasse 1, 40237 Düsseldorf, Germany; RWTH Aachen University, Sustainable Ferrous Metallurgy, Intzestrasse 1, 52072 Aachen, GermanySize, morphology and distribution of light and stiff, but inherently brittle particles are of critical importance for the property profile of high modulus steels. Powder atomisation can dramatically reduce the borides’ size to the nanoscale, but they typically coarsen substantially during annealing or compaction via hot isostatic pressing. This study investigated the effect of compaction parameters, namely temperature, pressure and time on the coarsening mechanism, porosity evolution and resultant mechanical properties of atomised Fe-Cr-B powder. Increasing annealing temperature and time from 950 to 1150 °C, respectively, 30 min to 8 h, resulted in a non-linear boride radius growth from 76 nm in the atomised state to 1.9 µm. Hot isostatic pressing, with additional pressures up to 140 MPa, decreased the pore size from about 5 to 0.2 µm. An optimised hot isostatic pressing processing window was defined at 1050 °C and 140 MPa, combining sufficiently reduced defects with a limited particle radius, and yielded in 730 MPa tensile strength at more than 20 % tensile elongation. Powder-metallurgical synthesis of Fe-Cr-B achieved similar properties to casted and hot-rolled material, by avoiding component size scaling effects of casting. The underlying phenomena and optimisation of high modulus steel production via powder metallurgy are discussed.http://www.sciencedirect.com/science/article/pii/S026412752400786XKinetic of growthBoridesAnnealingHot isostatic pressingLightweight designHigh modulus steels
spellingShingle M. Gathmann
D. Moisi
H. Springer
Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
Materials & Design
Kinetic of growth
Borides
Annealing
Hot isostatic pressing
Lightweight design
High modulus steels
title Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
title_full Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
title_fullStr Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
title_full_unstemmed Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
title_short Coarsening mechanism of M2B-borides and their effect on the mechanical properties of high modulus steels
title_sort coarsening mechanism of m2b borides and their effect on the mechanical properties of high modulus steels
topic Kinetic of growth
Borides
Annealing
Hot isostatic pressing
Lightweight design
High modulus steels
url http://www.sciencedirect.com/science/article/pii/S026412752400786X
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