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制备了增强相体积分数为5%~20%的系列Al72Ni12Co16P/A356准晶增强铝基复合材料。其中增强相Al72Ni12Co16通过将严格按化学成分配比的Al72Ni12Co16浇于水冷铜基板上激冷凝固而获得。TEM和XRD分析结果表明所获得的材料为单相准晶材料。准晶增强铝基复合材料经热挤压处理后,绝大部分的铸造缺陷被消除,力学性能测试显示当准晶相的加入量为20%时,铝基复合材料的抗拉强度、屈服强度、弹性模量等性能分别从基体材料的275 MPa、200 MPa和70 GPa提高至410 MPa、350 MPa和102 GPa,而延伸率却从6%降低至3%。分析了准晶增强铝基复合材料的断裂机制和增强机制,准晶颗粒增强铝基复合材料的断裂机制可能有如下3种:界面及其附近区域脱粘、基体在集中的滑移带内撕裂和颗粒断裂,而其增强机制主要是细晶强化、弥散强化和固溶强化。
A series of Al72Ni12Co16P / A356 quasicrystal reinforced aluminum matrix composites with enhanced phase volume fraction of 5% ~ 20% were prepared. The reinforcing phase Al72Ni12Co16 is obtained by pouring Al72Ni12Co16 strictly on the water-cooled copper substrate by the solidification. TEM and XRD results show that the obtained material is single-phase quasicrystalline material. Quasi-crystal reinforced aluminum matrix composite after hot extrusion treatment, the majority of casting defects are eliminated, the mechanical properties of the test showed that the amount of quasicrystalline phase is 20%, the tensile strength of aluminum matrix composites, yield strength , Elastic modulus and other properties increased from 275 MPa, 200 MPa and 70 GPa to 410 MPa, 350 MPa and 102 GPa, respectively, while elongation decreased from 6% to 3%. The fracture mechanisms and enhancement mechanisms of quasicrystal reinforced aluminum matrix composites are analyzed. The fracture mechanism of quasicrystal particle reinforced aluminum matrix composites may have the following three types: the interface and its vicinity are debonded, the matrix is torn within the concentrated slip band Crack and particle fracture, and its enhancement mechanism is mainly fine-grain strengthening, dispersion strengthening and solution strengthening.