Thermal Conductance of Graphene-Titanium Interface: A Molecular Simulation.

Bingxian Ou,Qinsheng Wang,Junxia Yan,Lixin Lu

doi:10.3390/molecules27030905

Abstract

Titanium is a commonly used material in aviation, aerospace, and military applications, due to the outstanding mechanical properties of titanium and its alloys. However, its relatively low thermal conductivity restricts its extended usage. The use of graphene as a filler shows great potential for the enhancement of thermal conductivity in titanium-based metal-matrix composites (MMCs). We used classical molecular dynamics (MD) simulation methods to explore the thermal conductance at the titanium–graphene (Ti/Gr) interface for its thermal boundary conductance, which plays an important role in the thermal properties of Ti-based MMCs. The effects of system size, layer number, temperature, and strain were considered. The results show that the thermal boundary conductance (TBC) decreases with an increasing layer number and reaches a plateau at n = 5. TBC falls under tensile strain and, in turn, it grows with compressive strain. The variation of TBC is explained qualitatively by the interfacial atomic vibration coupling factor. Our findings also provide insights into ways to optimize future thermal management based on Ti-based MMCs materials.

Highlights

Compared with other metals, titanium and its alloy derivatives are known for their excellent physical properties, stable chemical properties, and great biocompatibilities and are widely applied in aerospace [1], the military [2], automobile manufacturing [3], bone substitute manufacturing [4,5], and other fields
We study the thermal boundary conductance at the Ti/Gr interface using both non-equilibrium molecular dynamics (NEMD) and thermal relaxation (TR) methods
Our work suggests that the thermal properties of titanium can be greatly improved by affiliating an appropriate amount of graphene

Summary

Introduction

Titanium and its alloy derivatives are known for their excellent physical properties, stable chemical properties, and great biocompatibilities and are widely applied in aerospace [1], the military [2], automobile manufacturing [3], bone substitute manufacturing [4,5], and other fields. Due to outstanding properties, such as high thermal conductivity (~3000 Wm−1 K−1) [10,11], mechanical strength (~125 GPa) [12,13], and tensile modulus (~1.1 TPa) [14], graphene–metal materials exhibit high performance in thermal and mechanical properties and enhance the chemical stability of the metal [15,16,17,18,19,20]. The thermoelectric properties and mechanical stability of pure Ti and its alloys may be effectively enhanced by adding a certain amount of graphene. Zheng et al [31] reported that when 8 atomic layers of graphene were affiliated to the Gr/Ti composites, the interface thermal conductivity was as high as 440 MW/m2 K. Our work suggests that the thermal properties of titanium can be greatly improved by affiliating an appropriate amount of graphene. Compressive strain is an effective method to enhance the TBC of the Ti/Gr interface

Materials and Methods

Phonon Spectra

Results and Discussion

Temperature Effects

Effect of Strain Engineering