• 文献标题:   Temperature variations at nano-scale level in phase transformed nanocrystalline NiTi shape memory alloys adjacent to graphene layers
  • 文献类型:   Article
  • 作  者:   AMINI A, CHENG C, NAEBE M, CHURCH JS, HAMEED N, ASGARI A, WILL F
  • 作者关键词:  
  • 出版物名称:   NANOSCALE
  • ISSN:   2040-3364 EI 2040-3372
  • 通讯作者地址:   Deakin Univ
  • 被引频次:   9
  • DOI:   10.1039/c3nr01422c
  • 出版年:   2013

▎ 摘  要

The detection and control of the temperature variation at the nano-scale level of thermo-mechanical materials during a compression process have been challenging issues. In this paper, an empirical method is proposed to predict the temperature at the nano-scale level during the solid-state phase transition phenomenon in NiTi shape memory alloys. Isothermal data was used as a reference to determine the temperature change at different loading rates. The temperature of the phase transformed zone underneath the tip increased by similar to 3 to 40 degrees C as the loading rate increased. The temperature approached a constant with further increase in indentation depth. A few layers of graphene were used to enhance the cooling process at different loading rates. Due to the presence of graphene layers the temperature beneath the tip decreased by a further similar to 3 to 10 degrees C depending on the loading rate. Compared with highly polished NiTi, deeper indentation depths were also observed during the solid-state phase transition, especially at the rate dependent zones. Larger superelastic deformations confirmed that the latent heat transfer through the deposited graphene layers allowed a larger phase transition volume and, therefore, more stress relaxation and penetration depth.