【摘要】 采用Al-K₂TiF₆-KBF₄体系，制备了原位自生3%TiB₂/6061复合材料和0.3%Ce-3%TiB₂/6061（质量分数，下同）复合材料。采用SEM和TEM对复合材料显微组织进行观察，通过室温拉伸对复合材料进行力学性能测试，研究了Ce对原位自生TiB₂/6061复合材料显微组织及力学性能的影响。显微组织观察发现，TiB₂颗粒与6061基体间界面干净，结合稳定。Ce通过在不同晶面的吸附，改变了TiB₂颗粒的最终形貌，在颗粒表面出现倒角平台和圆弧角。Ce的加入缓解了颗粒团聚，团聚体的尺寸下降了38.68%,减小了复合材料基体晶粒尺寸，平均基体晶粒尺寸减小了56.50%。力学性能测试结果表明，3%TiB₂/6061复合材料的力学性能因0.3%Ce的加入得到明显提高，屈服强度提升了66.71%,抗拉强度提升了35.22%,伸长率提升了17.59%。经分析，在复合材料内部主要存在细晶强化、Orowan强化和热失配强化三种强化机制。更多还原

【Abstract】 In-situ synthesized 3% TiB₂/6061 composites and 0.3% Ce-3% TiB₂/6061 composites were fabricated by Al-K₂TiF₆-KBF₄ system.The microstructure of the composites was observed with SEM and TEM,and the mechanical properties of the composites were tested by room temperature tensile testing.The effect of Ce on the microstructure and tensile properties of in-situ synthesized TiB₂/6061 composites was studied.Microstructure observation reveals that the interface between TiB₂ particles and 6061 matrix is clean and the interfacial bonding is stable.Ce effected the final morphology of TiB₂ particles by adsorbing on different crystal planes,chamfering planes and arc corners appeared on the surface of TiB₂ particles.The addition of Ce alleviated particle agglomeration,the size of particle agglomeration decreased by 38.68% and the grain size of the composites decreased,with an average grain size decreased by 56.50%.The tensile test shows that the tensile properties of the 3% TiB₂/6061 composites are significantly improved by the addition of Ce,with YS increased by 66.71%,UTS increased by 35.22%,and EL increased by 17.59%.There are three main strengthening mechanisms in the composites:fine-grain strengthening,Orowan strengthening,and thermal expansion strengthening.更多还原