Molecular dynamics investigation of frictional decomposition behavior of HMX-tool interface in diamond cutting of HMX crystals

Abstract

Purpose This paper aims to reveal the tribochemical reaction mechanism on the nano-cutting interface between HMX crystal and diamond tool. Design/methodology/approach Molecular dynamics simulation of HMX crystal nano-cutting by the reactive force field is carried out in this paper. The affinity of activated atoms and friction damage at the different interface have been well identified by comparing two cutting systems with diamond tool or indenter. The analyses of reaction kinetics, decomposition products and reaction pathways are performed to reveal the underlying atomistic origins of tribocatalytic reaction on the nano-cutting interface. Findings The HMX crystals only undergo damage and removal in the indenter cutting, while they appear to accelerate thermal decomposition in the diamond cutting. the C-O affinity is proved to be the intrinsic reason of the tribocatalytic reaction of the HMX-diamond cutting system. The reaction activation energy of the HMX crystals in the diamond cutting system is lower, resulting in a rapid increase in the decomposition degree. The free O atoms can induce the asymmetric ring-opening mode and change the decomposition pathways, which is the underlying atomistic origins of the thermal stability of the HMX-diamond cutting system. Originality/value This paper describes a method for analyzing the tribochemical behavior of HMX and diamond, which is beneficial to study the thermal stability in the nano-cutting of HMX.

A review of advances in tribology in 2020–2021

“…In addition, some efforts have been done to provide theoretical support for the highly complex tribochemical process in the manufacturing. Cao et al [984] used ReaxFF MD simulation to analyze the tribochemical behavior, reaction kinetics, decomposition products during nano-cutting of octahydro-1,3,5,7tetranitro-1,3,5,7-tetrazocine (HMX) crystal by using diamond tool (Fig. 83(c)).…”

“…Fig 83. Reactive molecular dynamics simulations of tribochemistry at sliding interface[978,981,984,985]. Reproduced with permission from Ref [978],.…”

“…© The author(s), 2021; Reproduced with permission from Ref [981],. © Wiley-VCH GmbH, 2020; Reproduced with permission from Ref [984],. © Emerald Publishing Limited, 2021; Reproduced with permission from Ref [985],.…”

“…Reproduced with permission from Ref [984],. © Emerald Publishing Limited, 2021; Reproduced with permission from Ref [985],.…”