PSI - Issue 28

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ScienceDirect

Procedia Structural Integrity 28 (2020) 964–970 Structural Integrity Procedia 00 (2020) 000–000 Structural Integrity Procedia 00 ( 20) 000– 00

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© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract Tungsten alloys are often used in machinery and in other industrial sectors. This study presents the dynamic tensile behaviour of a commercial tungsten alloy. The tests were carried-out at high strain-rate (from 850 to 2200 s − 1 ) by means of a Split Hopkinson Tension Bar device on round specimens having diameter and gauge length of 2 mm and 5 mm, respectively. The dynamic stress versus strain curves were compared with the quasi-static ones in order to investigate the rate-dependency of this alloy. High strain rate caused a growth of proof and ultimate tensile strengths as well as modulus of toughness and a decrease of the area reduction. Finally, the parameters of the Cowper-Symonds relationship were calibrated. c 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY- C-ND license (http: // cr ativec mmons.org / licenses / by-nc-nd / 4.0 / ) -re ie unde responsibility of the European St uctural Integrity Society (ESIS) ExCo. Keywords: High strain-rate; tensile; Split Hopkinson Tensile Bar; tungsten alloy. 1st Virtual European Conference on Fracture High strain-rate behaviour of a Tungsten alloy Ezio Cadoni a, ∗ , Matteo Dotta a , Daniele Forni a a University of Applied Sciences of Southern Switzerland - DynaMat Laboratory, Campus SUPSI Trevano, Canobbio 6952, Switzerland Abstract Tungsten alloys are often used in machinery and in other industrial sectors. This study presents the dynamic tensile behaviour of a commercial tungsten alloy. The tests were carried-out at high strain-rate (from 850 to 2200 s − 1 ) by means of a Split Hopkinson Tension Bar device on round specimens having diameter and gauge length of 2 mm and 5 mm, respectively. The dynamic stress versus strain curves were compared with the quasi-static ones in order to investigate the rate-dependency of this alloy. High strain rate caused a growth of proof and ultimate tensile strengths as well as modulus of toughness and a decrease of the area reduction. Finally, the parameters of the Cowper-Symonds relationship were calibrated. c 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo. Keywords: High strain-rate; tensile; Split Hopkinson Tensile Bar; tungsten alloy. 1st Virtual European Conference on Fracture High strain-rate behaviour of a Tungsten alloy Ezio Cadoni a, ∗ , Matteo Dotta a , Daniele Forni a a University of Applied Sciences of Southern Switzerland - DynaMat Laboratory, Campus SUPSI Trevano, Canobbio 6952, Switzerland

1. Introduction 1. Introduction

Tungsten alloys are well-known for its outstanding thermal and mechanical characteristics such as hardness and wear resistance. In many manufacturing sector (i.e. tooling, drilling) cemented carbides represent the class of com posite materials more used because of their wear resistant properties (Arsecularatne et al. (2006)). One of the most used is the tungsten carbide (WC) cemented with cobalt (Co) as binder. The first represents the hard phase that gives hardness and wear resistance while the second is the matrix phase that provides strength and toughness. These alloys are subjected to severe regimes of strain-rate, for example in mining or in petroleum industries in order to enhance the rate of penetration and minimise the cost, tungsten carbide drill bits are subjected to increasing rotary speeds up to 200 rpm (Gupta (2013)). The main objective of this experimental study is to determine the mechanical response of a commercial tungsten alloy when subjected to high strain rate in tension. Tungsten alloys are well-known for its outstanding thermal and mechanical characteristics such as hardness and wear resistance. In many manufacturing sector (i.e. tooling, drilling) cemented carbides represent the class of com posite materials more used because of their wear resistant properties (Arsecularatne et al. (2006)). One of the most used is the tungsten carbide (WC) cemented with cobalt (Co) as binder. The first represents the hard phase that gives hardness and wear resistance while the second is the matrix phase that provides strength and toughness. These alloys are subjected to severe regimes of strain-rate, for example in mining or in petroleum industries in order to enhance the rate of penetration and minimise the cost, tungsten carbide drill bits are subjected to increasing rotary speeds up to 200 rpm (Gupta (2013)). The main objective of this experimental study is to determine the mechanical response of a commercial tungsten alloy when subjected to high strain rate in tension.

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.11.070 ∗ Corresponding author. Tel.: + 41-58-666-6377 ; fax: + 41-58-666-6359. E-mail address: ezio.cadoni@supsi.ch 2210-7843 c 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo. ∗ Corresponding author. Tel.: + 41-58-666-6377 ; fax: + 41-58-666-6359. E-mail address: ezio.cadoni@supsi.ch 2210-7843 c 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo.