TY - JOUR

T1 - Enhancing mechanical properties of ultrafine-grained tungsten for fusion applications

AU - Wurmshuber, Michael

AU - Doppermann, Simon

AU - Wurster, Stefan

AU - Jakob, Severin

AU - Balooch, Mehdi

AU - Alfreider, Markus

AU - Schmuck, Klemens Silvester

AU - Bodlos, Rishi

AU - Romaner, Lorenz

AU - Hosemann, Peter

AU - Clemens, Helmut

AU - Maier-Kiener, Verena

AU - Kiener, Daniel

N1 - Publisher Copyright: © 2023 The Authors

PY - 2023/2

Y1 - 2023/2

N2 - Tungsten, while showing many favorable properties, faces challenges in high-performance applications due to its brittle nature. One strategy to improve strength and toughness in tungsten is to refine the grain size down to the ultra-fine grained (ufg) regime. However, as the grain size is reduced, the fraction of grain boundaries that provide easy paths for crack growth increases, thereby limiting the gain in ductility. Therefore, strengthening the grain boundaries is of great importance if one wants to tap the full potential of this material. Using ab-initio calculations, potential grain boundary cohesion enhancing doping elements were identified, and doped ultra-fine grained tungsten samples were fabricated from powders and characterized extensively using small-scale testing techniques. We found that additions of boron and hafnium improve the mechanical properties of tungsten remarkably. Furthermore, an additional low-temperature heat treatment of the boron-doped sample promotes grain boundary segregation, enhancing the properties even further. Thus, in this work we provide an effective pathway of improving mechanical properties in ultra-fine grained tungsten using grain boundary segregation engineering. This opens the door for many challenging applications of ufg W in harsh environments. To further underline the potential employment of ufg W in nuclear fusion reactors, a favorable swelling behavior and mechanical property response after irradiation with helium is presented within this work.

AB - Tungsten, while showing many favorable properties, faces challenges in high-performance applications due to its brittle nature. One strategy to improve strength and toughness in tungsten is to refine the grain size down to the ultra-fine grained (ufg) regime. However, as the grain size is reduced, the fraction of grain boundaries that provide easy paths for crack growth increases, thereby limiting the gain in ductility. Therefore, strengthening the grain boundaries is of great importance if one wants to tap the full potential of this material. Using ab-initio calculations, potential grain boundary cohesion enhancing doping elements were identified, and doped ultra-fine grained tungsten samples were fabricated from powders and characterized extensively using small-scale testing techniques. We found that additions of boron and hafnium improve the mechanical properties of tungsten remarkably. Furthermore, an additional low-temperature heat treatment of the boron-doped sample promotes grain boundary segregation, enhancing the properties even further. Thus, in this work we provide an effective pathway of improving mechanical properties in ultra-fine grained tungsten using grain boundary segregation engineering. This opens the door for many challenging applications of ufg W in harsh environments. To further underline the potential employment of ufg W in nuclear fusion reactors, a favorable swelling behavior and mechanical property response after irradiation with helium is presented within this work.

UR - https://pure.unileoben.ac.at/portal/en/publications/enhancing-mechanical-properties-of-ultrafinegrained-tungsten-for-fusion-applications(ad4bd929-6c1f-430c-959d-30abb9acaaf6).html

U2 - 10.1016/j.ijrmhm.2023.106125

DO - 10.1016/j.ijrmhm.2023.106125

M3 - Article

VL - 111.2023

JO - International journal of refractory metals & hard materials

JF - International journal of refractory metals & hard materials

SN - 0263-4368

IS - February

M1 - 106125

ER -