TY - JOUR
T1 - Effects of aging temperature on electrical conductivity and hardness of Cu-3 at. pct Ti alloy aged in a hydrogen atmosphere
AU - Semboshi, S.
AU - Nishida, T.
AU - Numakura, H.
AU - Al-Kassab, Tala'at
AU - Kirchheim, R.
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2011/2/25
Y1 - 2011/2/25
N2 - To improve the balance of the electrical conductivity and mechanical strength for dilute Cu-Ti alloys by aging in a hydrogen atmosphere, the influence of aging temperature ranging from 673 K to 773 K (400 °C to 500 °C) on the properties of Cu-3 at. pct Ti alloy was studied. The Vickers hardness increases steadily with aging time and starts to fall at 3 hours at 773 K (500 °C), 10 hours at 723 K (450 °C), or over 620 hours at 673 K (400 °C), which is the same as the case of conventional aging in vacuum. The maximum hardness increases from 220 to 236 with the decrease of aging temperature, which is slightly lower than aging at the same temperature in vacuum. The electrical conductivity at the maximum hardness also increases from 18 to 32 pct of pure copper with the decrease of the temperature, which is enhanced by a factor of 1.3 to 1.5 in comparison to aging in vacuum. Thus, aging at 673 K (400 °C) in a hydrogen atmosphere renders fairly good balance of strength and conductivity, although it takes nearly a month to achieve. The microstructural changes during aging were examined by transmission electron microscopy (TEM) and atom-probe tomography (APT), it was confirmed that precipitation of the Cu4Ti phase occurs first and then particles of TiH2 form as the third phase, thereby efficiently removing the Ti solutes in the matrix.
AB - To improve the balance of the electrical conductivity and mechanical strength for dilute Cu-Ti alloys by aging in a hydrogen atmosphere, the influence of aging temperature ranging from 673 K to 773 K (400 °C to 500 °C) on the properties of Cu-3 at. pct Ti alloy was studied. The Vickers hardness increases steadily with aging time and starts to fall at 3 hours at 773 K (500 °C), 10 hours at 723 K (450 °C), or over 620 hours at 673 K (400 °C), which is the same as the case of conventional aging in vacuum. The maximum hardness increases from 220 to 236 with the decrease of aging temperature, which is slightly lower than aging at the same temperature in vacuum. The electrical conductivity at the maximum hardness also increases from 18 to 32 pct of pure copper with the decrease of the temperature, which is enhanced by a factor of 1.3 to 1.5 in comparison to aging in vacuum. Thus, aging at 673 K (400 °C) in a hydrogen atmosphere renders fairly good balance of strength and conductivity, although it takes nearly a month to achieve. The microstructural changes during aging were examined by transmission electron microscopy (TEM) and atom-probe tomography (APT), it was confirmed that precipitation of the Cu4Ti phase occurs first and then particles of TiH2 form as the third phase, thereby efficiently removing the Ti solutes in the matrix.
UR - http://hdl.handle.net/10754/334620
UR - http://link.springer.com/10.1007/s11661-011-0637-8
UR - http://www.scopus.com/inward/record.url?scp=79959542546&partnerID=8YFLogxK
U2 - 10.1007/s11661-011-0637-8
DO - 10.1007/s11661-011-0637-8
M3 - Article
SN - 1073-5623
VL - 42
SP - 2136
EP - 2143
JO - Metallurgical and Materials Transactions A
JF - Metallurgical and Materials Transactions A
IS - 8
ER -