Abstract
TiAl alloy represents a new class of light and heat-resistant materials. In this study, the effect of temperature, pressure, and grain size on the high-temperature creep properties of nanocrystalline TiAl alloy have been studied through the molecular dynamics method. Based on this, the deformation mechanism of the different creep stages, including crystal structure, dislocation, and diffusion, has been explored. It is observed that the high-temperature creep performance of nanocrystalline TiAl alloy is significantly affected by temperature and stress. The higher is the temperature and stress, the greater the TiAl alloy’s steady-state creep rate and the faster the rapid creep stage. Smaller grain size accelerates the creep process due to the large volume fraction of the grain boundary. In the steady-state deformation stage, two kinds of creep mechanisms are manly noted, i.e., dislocation motion and grain boundary diffusion. At the same temperature, the creep mechanism is dominated by the dislocation motion in a high-stress field, and the creep mechanism is dominated by the diffusion creep in the low-stress field. However, it is observed to be mainly controlled by the grain boundary diffusion and lattice diffusion in the rapid creep stage.
Highlights
TiAl alloy exhibits the advantages of low density, high stiffness, heat-resistance, and excellent anti-oxidative character
During the evolution of the crystal structure, the extent of amorphization of the grains in TiAl alloy continuously increases during the creep process, which leads to a gradual increase in the proportion of the amorphous components in the model with time
The molecular dynamics simulation has been used to analyze the factors affecting the creep properties of TiAl alloy at high temperatures
Summary
TiAl alloy exhibits the advantages of low density, high stiffness, heat-resistance, and excellent anti-oxidative character. The effects of factors like temperature, stress, and grain size on the high temperature creep properties of nanocrystalline TiAl alloy have been studied. .TThheesstutuddyyhhaassaaddooppteteddththeecceennteterrssyymmmmeetrtryy parameters (CSP) [28] to calculate the local atomic damage, providing insights into the crystal structure evolution for the high-temperature creep process of the nanocrystalline TiAl alloy. Nanomaterials 2020, 10, 1693 parameters (CSP) [28] to calculate the local atomic damage, providing insights into the crystal structure evolution for the high-temperature creep process of the nanocrystalline TiAl alloy. Based on the creep curve, it can be intuitively suggested that increasing the temperature and stress enhances the steady state-creep rate in the high-temperature creep process, accelerating the advent of the rapid creep stage and shortening the creep life of TiAl alloy. When the GB volume fraction becomes larger in the smaller GS samples, the creep rate increases
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
