FSP制备TiO_(2)铝基复合材料的组织与性能研究

Study on the microstructure and properties of TiO_(2)/Al composites prepared by FSP

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TiO_(2)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,TiO_(2)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TiO_(2)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TiO_(2)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。

In order to solve the problem of strength and toughness of aluminum matrix composites,TiO_(2)/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 TiO_(2),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%.TiO_(2)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.