Study of the tensile behaviour of tungsten wires from ambient temperature to 320 °C in relation to their microstructure

• Published in: International journal of refractory metals & hard materials Vol. 92; p. 105325
• Main Authors: Michel, R., Bienvenu, Y., Chesnaud, A., Thorel, A.
• Format: Journal Article
• Language: English
• Published: Shrewsbury Elsevier Ltd 01.11.2020; Elsevier BV; Elsevier
• Subjects: Ambient temperature; Axial stress; Damage localization; Engineering Sciences; Hoop stress; Mechanical properties; Microstructure; Necking; Notch sensitivity; Rupture; Tensile fracture mode; Tensile tests; Texture; Tungsten; Tungsten wire; Tungsten wire; Tensile fracture mode; Microstructure; Texture
• ISSN: 0263-4368; 2213-3917
• DOI: 10.1016/j.ijrmhm.2020.105325

The tensile test results have been interpreted in terms of the microstructure typical of drawn tungsten wires; the influence of test temperature between 25 °C and 320 °C is significant and is linked to the dependence of the mechanical behaviour of tungsten versus temperature and to the development with increasing temperature of a necking zone in which damage and rupture take place in two stages, a localized damage controlled first by the hoop stress associated to the notch effect linked to necking and rupture under the axial stress and the notch effect just mentioned. •The damage and rupture mechanisms are closely linked to the microstructure of the drawn wire•With increasing temperature, yield stress, max stress and rupture elongation decrease as as the striction zone becomes more important•The initial W wire damage mechanism is by intergranular decohesion in the striction zone•Final rupture is about normal to the tensile axis but the fracture surface is not planar due to intergranular decohesion•The damage mechanisms during tensile test results also operate in the shaping and working of round W wire by forging, rolling