通过低压渗透法制备SiC长纤维强化Al基合金的复合材料及其弯曲强度的研究

Research on Preparation of SiC Long Fiber Reinforced Al-Based Alloy Composites by Low Pressure Infiltration and Its Flexural Strength

采用低压渗透法制备SiC长纤维增强铝合金基复合材料(FRMMC)并检测其弯曲强度的性能。加压渗透时,渗透压强等于强化纤维间毛细管压强和黏性抵抗之和,文中通过纯Al粒子与熔融Al基合金接触后,形成空隙增加了强化材料间间距,从而降低其所需要的最小压强。通过不同尺寸的Al粒子与强化纤维混合,模拟计算并观测了当强化纤维与Al粒子尺寸的变化与SiC纤维在基体合金中分布的均一性关系。结果表明:当SiC与Al粒子尺寸一致时,其实际弯曲强度与理论值相接近。当Al粒子尺寸小于纤维时,SiC纤维呈不均匀分布。此外,SiC/Al间的界面反应层没有降低复合材料的整体力学性能。

In this paper, SiC long fiber reinforced aluminium alloy matrix composites(FRMMC) are prepared by low pressure infiltration method and their bending strength is tested. The osmotic pressure is equal to the sum of the capillary pressure and the viscous resistance between the strengthened fibers. In this paper, after contacting Al particles with the molten alloy, the space between the strengthened materials is increased, thus the minimum pressure required is reduced.The homogeneity of SiC fibers in matrix alloys is simulated and observed by mixing Al particles of different sizes with reinforced fibers when the sizes of reinforced fibers are the same as those of Al particles. The results show that the actual bending strength is close to the theoretical value. When the size of Al particles is smaller than that of fibers, the distribution of SiC fibers is inhomogeneous. In addition, the interfacial reaction layer between SiC and Al does not reduce the overall mechanical properties of the composites.