TY - JOUR
T1 - Length-scale-dependent nanoindentation creep behaviour of Ti/Al multilayers by magnetron sputtering
AU - Fu, Kunkun
AU - Sheppard, Leigh R.
AU - Chang, Li
AU - An, Xianghai
AU - Yang, Chunhui
AU - Ye, Lin
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/5
Y1 - 2018/5
N2 - This study presented length-scale-dependent room temperature creep behaviour of Ti/Al multilayers by nanoindentation. Ti/Al multilayers with individual layer thickness ranging from 10 nm to 250 nm were prepared by a direct current magnetron sputtering method. Microstructural analysis showed that the prepared Ti/Al multilayers were polycrystalline, with strong Ti (0002) and Al (111) texture. Nanoindentation creep tests were performed to examine the time-dependent creep deformation, stress exponent, creep strain rate sensitivity and contact creep compliance of the multilayers at room temperature. It was found that both the maximum creep deformation and the creep strain rate sensitivity increase with an increase in the individual layer thickness, indicating a length-scale-dependent creep behaviour of the Ti/Al multilayers. The values of stress exponent were found to lay in the range of 15.74-61.46, implying that the creep behaviour of the multilayers was controlled by the dislocation creep mechanism. Finally, the contact creep compliances of the Ti/Al multilayers were well modelled by a two-element Kelvin-Voigt model. From this, it was determined that the creep numbers and retardation times increased with increased individual layer thickness.
AB - This study presented length-scale-dependent room temperature creep behaviour of Ti/Al multilayers by nanoindentation. Ti/Al multilayers with individual layer thickness ranging from 10 nm to 250 nm were prepared by a direct current magnetron sputtering method. Microstructural analysis showed that the prepared Ti/Al multilayers were polycrystalline, with strong Ti (0002) and Al (111) texture. Nanoindentation creep tests were performed to examine the time-dependent creep deformation, stress exponent, creep strain rate sensitivity and contact creep compliance of the multilayers at room temperature. It was found that both the maximum creep deformation and the creep strain rate sensitivity increase with an increase in the individual layer thickness, indicating a length-scale-dependent creep behaviour of the Ti/Al multilayers. The values of stress exponent were found to lay in the range of 15.74-61.46, implying that the creep behaviour of the multilayers was controlled by the dislocation creep mechanism. Finally, the contact creep compliances of the Ti/Al multilayers were well modelled by a two-element Kelvin-Voigt model. From this, it was determined that the creep numbers and retardation times increased with increased individual layer thickness.
KW - magnetron sputtering
KW - nanostructured materials
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:45876
U2 - 10.1016/j.matchar.2018.02.041
DO - 10.1016/j.matchar.2018.02.041
M3 - Article
SN - 1044-5803
VL - 139
SP - 165
EP - 175
JO - Materials Characterization
JF - Materials Characterization
ER -