Micro-and Nano-Scopic Wave Theoretical Approach to Thermal Contact Resistance of Solid Interfaces

固体表面间的接触热阻是工业设备热设计和安全控制的重要因素之一。不仅需要在热物理理论和波动理论的基础上对接触热阻现象进行系统的澄清基础研究，而且需要开发一种在线非接触诊断技术来诊断接触热阻的瞬态现象。2002-2003年，我们从这个角度进行了以下两项研究：第一，我们进行了一项实验研究，以检查诊断技术，从外部诊断接触热阻的过程中和非接触。由于接触界面的微观几何形状在每一个时刻对应于施加到表面系统的压力和晶体结构的弹性/塑性变形而变化，因此开发一种技术来估计两个固体表面之间的接触状态变得重要。我们应用 ...更多信息 超声波检测技术的应用。在本实验研究中，宏观基础实验，以测量金属-金属（黄铜-SKD 61工具钢）接触界面的真实接触面积，超声波在接触界面的反射和透射以及穿过接触界面的热传输，进行。通过对超声波反射率和透射率-接触热阻或接触热导率-接触面积三个物理量之间关系的定量分析，阐明了压力参数对接触热阻现象的影响。其次，对接触热阻现象进行了一系列的分子动力学模拟，阐明了接触热阻现象的微观机理。在MEMS系统中，存在于两个均匀晶体原子层界面处的接触热阻称为“界面热阻”。为了探讨其详细的机制，计算了弹性波穿过两个不同颗粒质量的模型晶体与硅衬底上的硅酸盐薄膜之间的界面的阻尼传播。我们新近发展了一种用小波变换技术分析晶格振动的方法，并证明了弹性波的传播受到原子界面的阻碍。所得到的晶格振动的寿命被发现是依赖于它的频率。结合态密度、弹性波速度和寿命，估算了界面热阻。少

Thermal contact resistance between two solid surfaces is one of the most important factors in thermal design and safety control in industrial devices. It is necessary not only to perform a basic research on clarification of thermal contact resistance phenomena systematically in the basis of thermal physics theory and wave theory, but also to develop a in-process non-contact diagnosis technique to diagnose transient phenomena of thermal contact resistance. In 2002-2003, we have studied the following two researches from this point of view :First, we have performed an experimental study to examine a diagnosis technique to diagnose thermal contact resistance from outside in-processly and non-contactly. Since microgeometry of contact interface changes at every moment corresponding with applied pressure to the surface system and elastic/plastic deformation of crystal structure, it becomes important to develop a technique to estimate contact states between two solid surfaces. We have applied … More the ultrasonic wave inspection technique to this purpose. In this experimental study, macro-scopic fundamental experiments to measure true contact areas of metal-metal (brass-SKD61 tool steel) contact interfaces, ultrasonic wave reflection and transmission in the contact interfaces and heat transmission crossing the contact interfaces, were performed. Relationships among three physical quantities, that is, (ultrasonic wave reflectance and transmittance) -(thermal contact resistance or thermal contact conductance) -(true contact areas), are clarified quantitatively throughout a parameter of applied pressure.Second, we have performed a series of molecular dynamics simulations to clarify microscopic mechanism of thermal contact resistance phenomena. Thermal contact resistance existing at an interface of two homogeneous crystal atomic layers in MEMS systems is called 'interface thermal resistance'. To investigate its detailed mechanism, damping propagation of elastics waves crossing an interface between two model crystals with different particle mass and a silicate film on silicon substrate were calculated. We have newly developed a lattice vibration analysis with wavelet transform technique, and have shown that propagation of elastic waves is hindered by the atomic interface. The obtained lifetime of the lattice vibration is found to be dependent on its frequency. With the density of states, the speed of elastic waves, and the lifetime combined, the interfacial thermal resistance was estimated. Less