【摘要】 为了解决铝基复合材料强韧性的问题，采用搅拌摩擦加工（friction stir processing, FSP）的方法制备TiO₂铝基复合材料。分别采用显微组织观察试验、拉伸试验和显微硬度试验等方法，对复合材料的强化机理、显微组织以及力学性能进行表征与分析。结果表明，TiO₂的加入对复合材料具有细化晶粒作用，FSP改变了铝合金的结晶形式，由无形核的连续性动态再结晶转变为颗粒刺激形核机制；FSP制备TiO₂铝基复合材料的抗拉强度及显微硬度均得到了提高，当添加量达到4.8%（质量分数）时，复合材料的抗拉强度达到456 MPa,硬度值达到130 HV,与未添加颗粒相比较，分别提高了17%和16%,而延伸率仅下降了4%。FSP制备TiO₂铝基复合材料不仅可以有效提高力学性能，可以改善强韧性不匹配的问题，研究结果可为新型复合材料的应用提供理论基础和技术参考。更多还原

【Abstract】 In order to solve the problem of strength and toughness of aluminum matrix composites, TiO₂/Al matrix composites were prepared by friction stir processing（FSP）. The experiments were carried out by microstructure observation test, tensile test and micro-hardness test to characterize and analyze the strengthening mechanism, microstructure and mechanical properties of composites. The results show that with the introduction of TiO₂, the grain has been refined, and the crystalline form of Al is change from continuous dynamic recrystallization（CDRX） of invisible core to the particle-stimulated nucleation mechanism by FSP. The tensile strength and microhardness of the composite are improved. When the addition amount reaches 4.8%（mass fraction）, the tensile strength is 456 MPa, and the hardness is 130 HV, which increases by 17% and 16%, respectively, compared with that of the unadded particles, and the elongation decreases only by 4%. TiO₂ prepared by FSP can effectively improve the mechanical properties and improve the strength and toughness mismatch, which provides theoretical basis and technical reference for the application of new composite materials.更多还原