ABSTRACT In this work, the desensitising effect of water film on the diamond cutting of HMX crystal is studied by using reactive force field (ReaxFF) molecular dynamics simulations. The lubrication behavior, reaction kinetics, decomposition products and reaction pathways are particularly studied to reveal the underlying atomistic origins of desensitisation of wet-cutting system. Simulation results show that a film lubrication and its evolutionary behaviour occur at the nano-cutting interface. And forming a complete water-lubricating film is critical for improving thermal stability of the entire cutting system, which is correlated to tool sharpness, HMX properties and water-lubrication method in the actual cutting process. More interestingly, the mechanism of desensitising effect is confirmed to be that the nano-water film inhibits the C–O affinity between diamond tool and HMX, which makes the relatively stable symmetric cleavage of the main ring dominant in the initial decomposition of HMX. Although the type and evolution trend of the decomposition product is similar to that in dry cutting, the degree of decomposition and the severity of HMX are lower in wet-cutting, and the presence of water-lubricating film causes the transition of main dynamic mechanism function of the HMX from the self-catalysed mode into the random nucleation mode.

中文翻译：

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ReaxFF MD模拟纳米切割条件下水膜对HMX晶体初始分解的脱敏作用

摘要 在这项工作中，利用反作用力场（ReaxFF）分子动力学模拟研究了水膜对 HMX 晶体金刚石切割的脱敏效应。特别研究了润滑行为、反应动力学、分解产物和反应途径，以揭示湿切割系统脱敏的潜在原子起源。模拟结果表明，薄膜润滑及其演化行为发生在纳米切割界面。而形成完整的水润滑膜对于提高整个切削系统的热稳定性至关重要，这与实际切削过程中的刀具锋利度、HMX性能和水润滑方法有关。更有趣的是，脱敏效应的机制被证实是纳米水膜抑制了金刚石工具和 HMX 之间的 C-O 亲和力，这使得主环的相对稳定的对称解理在 HMX 的初始分解中占主导地位。虽然分解产物的类型和演化趋势与干切削相似，但湿切削中HMX的分解程度和严重程度较低，并且水润滑膜的存在导致主要动力机制函数的转变HMX 从自催化模式转变为随机成核模式。