Abstract

This work is aimed at solving the challenging problem of developing an approach to determining the representative volume of an Al/SiC metal matrix composite material (MMC) with 55 vol % silicon carbide synthesized by a unique squeeze casting technology. This volume is referred to as representative volume element (RVE). Initially, the minimum unit cell size was found by a metallographic method. The RVE of the MMC, where the average filler content is equal to the average filler content in the composite material, begins with a 40 × 40-μm region. The RVE is determined by the finite element method. To perform numerical RVE calculations, we solved the two-dimensional problem of tension an element in the cross section of the MMC consisting of hard SiC particles and a pure aluminum matrix. A stress–strain curve recorded during uniaxial tension is used as the response of MMC to an external action. The problems with regions of 40 × 40, 50 × 50, 70 × 70, 100 × 100, 200 × 200 and 400 × 400 μm are solved. The results of the numerical calculations demonstrate that the minimum RVE of the Al/SiC MMC with 55 vol % silicon carbide is 200 × 200 μm. In addition, depth-sensing indentation is recommended as an experimental method for estimating RVE. When a pyramidal indenter is pressed into the surface of an MMC sample, the indentation diagram reflects the influence of both the composite matrix and silicon carbide particles. The indentation force (correspondingly, surface area) used in experiments is such that the influence of the site of indentation on the indentation diagram is minimal. Instrumented indentation used to determine RVE demonstrates that it is 200 × 200 × 200 μm.

中文翻译：

---

确定挤压铸造Al / SiC金属基复合材料代表体积元素的方法开发

摘要

这项工作旨在解决具有挑战性的问题，即开发一种方法来确定通过独特的挤压铸造技术合成的具有55％体积百分比的碳化硅的Al / SiC金属基复合材料（MMC）的代表性体积。该体积称为代表性体积元素（RVE）。最初，最小的晶胞尺寸是通过金相方法找到的。MMC的RVE，其中平均填料含量等于复合材料中的平均填料含量，始于40×40μm区域。RVE由有限元方法确定。为了执行RVE数值计算，我们解决了由硬质SiC颗粒和纯铝基体组成的MMC截面中的元素受拉的二维问题。单轴拉伸过程中记录的应力-应变曲线被用作MMC对外部作用的响应。解决了40×40、50×50、70×70、100×100、200×200和400×400μm区域的问题。数值计算结果表明，具有55体积％的碳化硅的Al / SiC MMC的最小RVE为200×200μm。另外，推荐使用深度感应压痕作为估算RVE的实验方法。当将锥形压头压入MMC样品的表面时，压痕图反映了复合基质和碳化硅颗粒的影响。实验中使用的压痕力（相应地，表面积）应使压痕部位对压痕图的影响最小。