界面性能对原位颗粒增强铝基复合材料弹性模量的影响

发布时间：2018-01-05 08:51

本文关键词：界面性能对原位颗粒增强铝基复合材料弹性模量的影响　出处：《江苏大学》2015年硕士论文　论文类型：学位论文

【摘要】：原位颗粒增强铝基复合材料以其优异的力学性能和物理性能、易于制造加工以及显著的低成本优势而成为复合材料研究热点之一。界面性能对复合材料的弹性模量有着显著的影响,而目前的研究对象多是外加颗粒增强铝基复合材料,本文对原位颗粒增强铝基复合材料的微观组织及其弹性模量进行了实验研究。在实验研究的基础上,建立三维及二维RVE有限元模型,结合混合律模型,数值模拟计算了界面等微观结构参数对原位颗粒增强铝基复合材料弹性模量的影响。通过实验测量值与有限元模型模拟值相对比,验证了有限元模型的合理性,并运用该模型模拟预测了界面性能及界面模量梯度对原位SiCp/7075复合材料弹性模量的影响规律,具体研究内容如下：(1)采用熔体反应法实验制备了原位TiB2/A356复合材料,用JSM-7001F扫描电镜对其进行了扫描观察,并用电子万能试验机对各组试样进行了拉伸实验,测得了其弹性模量。建立三维及二维RVE有限元模型,结合混合律模型,数值模拟计算了界面性能对原位TiB2/A356复合材料弹性模量的影响并得出复合材料细观单元应力-应变场分布细节。将实验测得TiB2/A356复合材料弹性模量值与数值模型预测值相比较,验证了所建立有限元模型的合理性,并用该模型预测了界面性能对颗粒体积分数比较大的TiB2/A356复合材料弹性模量的影响情况。(2)应用经过实验验证的有限元模型数值模拟研究了界面性能对原位SiCp/7075复合材料弹性模量的影响规律,研究发现：界面性能可以显著的影响复合材料的弹性模量,并且颗粒体积分数越大界面性能的影响越显著,界面模量与基体模量需要满足的比值与颗粒体积分数有关,并不局限于20%-30%之间；当颗粒体积分数较大时,与界面纯弹性相比,界面弹塑性会较明显的降低原位铝基复合材料的弹性模量。(3)由于界面层的性能是随着位置而连续变化的,本文假设界面模量梯度函数为一次函数,并在数值计算时,对该函数进行离散化,采用对界面进行分层的方法建立了界面模量梯度变化的轴对称RVE模型,研究发现,界面模量呈梯度变化的原位铝基复合材料弹性模量的预测结果要比对应的均匀界面层的复合材料弹性模量预测值要小。
[Abstract]:In situ particle reinforced aluminum matrix composites with excellent mechanical properties and physical properties, easy manufacturing and processing as well as significant cost advantage and become a hot research topic. The composite has a significant impact on the interfacial properties of elastic modulus of composite materials, and the research object is present with particle reinforced aluminum matrix composite in this paper the in situ particle reinforced microstructure and elastic modulus of aluminum matrix composites were studied. On the basis of experimental results, RVE finite element model of 2D and 3D, with mixed law model, numerical simulation of interface microstructure parameters such as elastic modulus of reinforced aluminum matrix composites in situ with finite particles. Element model of simulation is obtained by comparing the experimental measurements to verify the rationality of the finite element model, and using the model to simulate the interfacial properties and mask industry forecast Effect of gradient on the elastic modulus of in situ SiCp/7075 composites, the specific contents are as follows: (1) TiB2/A356 in situ composites were prepared by melt reaction method experiment, the scanning observation of the JSM-7001F scanning electron microscope and electronic universal testing machine samples of each group were measured the tensile test, the elastic modulus the establishment of RVE. The finite element model of 2D and 3D, with mixed law model, numerical simulation of the influence of interfacial properties on the elastic modulus of TiB2/A356 in situ composite and the composite meso element stress-strain field distribution in detail. The measured TiB2/A356 composite elastic modulus values are compared with the numerical prediction model to verify the rationality of the finite element model is established, and the model was used to predict the interfacial performance of the elastic modulus of TiB2/A356 composites than the larger particle volume fraction. Ring. (2) numerical application after experimental verification of the finite element model are investigated by simulation, interfacial properties on the elastic modulus of SiCp/7075 in situ composite research found that the interface performance can significantly affect elastic modulus of composite materials, and the effects of the particle volume fraction is the interface properties of the more significant interface matrix modulus ratio to meet the ratio and the volume fraction of the particles, is not limited to 20%-30%; when the particle volume fraction is larger, compared with the pure elastic interface, the interface plastic will reduce the elastic modulus of in-situ aluminum matrix composite is obvious. (3) the performance of the interface layer is with the continuous change of the position. It is assumed that the surface modulus gradient function as a function, and the numerical calculation, discretization of the function, established the interface by using the method of stratified modulus gradient of the interface Based on the axisymmetric RVE model, it is found that the prediction of elastic modulus of In-situ Aluminum Matrix Composites with gradient changes of interfacial modulus is smaller than that of corresponding composite interfaces.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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