金刚石/铜复合材料的界面热残余应力与界面热导的耦合关联机制研究

In this project, the relationship between the thermal residual stress near the interface and thermal conductivity are investigated by both the experiments and finite element theory, starting with control of the thermal residual stress. The thermal residual stress is changed with cooling and heating cycles. Impacted by different residual stress, dislocation density may change, which will dramatically affect the thermal conductivity of electron and phonon in the diamond/Cu composites. Thus, the effect and mechanism between thermal residual stress and thermal conductivity of the diamond/Cu is concluded. Then, involved with the dislocation density and the effective radius of the thermal residual stain region , the thermal conductivity of the diamond/Cu interface is calculated by the finite element theory and the Diffuse Mismatch model . The object of program has the great significance of theory and application for designing, predicting and controlling the fabrication and thermal conductivity of diamond/Cu composites.

本项目拟从热残余应力的调控入手，从实验和有限元理论分析两个方面建立金刚石增强复合材料的界面热残余应力与界面热导的关联机制和量化关系。通过对金刚石/铜界面样品冷热循环处理，实现金刚石/铜界面热残余应力的调控；表征不同热残余应力作用下界面处的热残余应力分布以及位错分布情况，探究电子和声子在界面微观缺陷的传导情况，深层次揭示金刚石增强铜基复合材料界面热残余应力与界面热导的耦合关联。之后建立金属－非金属界面处等效界面模型，引入位错密度与热残余应变区有效半径作为内变量，有限元模拟结合散射不匹配模型计算金刚石/铜的界面热导，揭示金刚石/铜界面热残余应力与界面热导之间的量化关系。项目的开展对设计、预测和控制金刚石/铜复合材料的制备及热导性能具有重要的理论意义和实用价值。

界面问题是金属基复合材料制备科学首要关键科学问题。本项目聚焦界面热导问题，从热残余应力的调控入手，从实验和有限元理论分析两个方面研究了金刚石增强复合材料的界面热残余应力与界面热导的关联机制和量化关系。首先结合理论推导和有限元方法、魏德曼-弗兰兹定律、马西森定律，得到了基体金属热导率和应变的关系式。其次，使用三维软件建立了球形颗粒面心立方分布的复合材料模型，并且收集了Cu/金刚石的相关界面计算参数，最后通过用户子程序将理论公式加入到有限元方法中进行热力耦合的模拟，确定了具体的分析步和边界条件的设置。最终得到了准确性和稳定性高的颗粒增强金属基复合材料热导模型和考虑界面热残余应力的Cu/金刚石热导模型。通过模型预测的热导率值与实验值基本吻合，且预测稳定性相比别的模型显著提高。项目的开展对设计、预测和控制金刚石/铜复合材料的制备及热导性能具有重要的理论意义和实用价值。