Al_(72) Ni_(12)Co_(16)/A365准晶颗粒增强铝基复合材料的制备及其力学性能

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。

Preparation and mechanical properties of Al_(72)Ni_(12)Co_(16)/A365 quasicrystal particle reinforced Al matrix composites

Al matrix composites with Al_(72)Ni_(12)Co_(16) particles of volume fraction ranging from 5% ～ 20% were prepared. The quasierystal material was obtained by casting Al_(72) Ni_(12) Co_(16) alloy on the water cooling copper substrate. TEM and X- ray diffraction analysis indicate that the obtained material is single- phase quasicrystal material. Most defects of as-cast composites are eliminated by the hot extrusion, and the mechanical property test reveals that with addition of Al_(72) Ni_(12) Co_(16), the tensile strength, yield strength and elastic modulus of Al matrix composites increase remarkably from 275 MPa, 200 MPa and 70 GPa to 410 MPa, 350 MPa and 102 GPa, respectively; on the other hand, the elongation decreases from 6% to 3%. Based on the above experiment, the fracture mechanism and strengthening mechanism were discussed in detail.