摘要
结合机械球磨和热变形工艺制备具有反贝壳结构的SiC/AZ31复合材料,通过工艺控制对复合材料微观结构进行有效调控。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)等对材料的微观结构进行表征,通过准静态拉伸实验测试材料的力学性能,并结合其微观形貌对强韧化机理与失效机制进行初步分析。结果表明:通过热变形工艺获得的反贝壳结构可以明显提升镁基复合材料的拉伸性能;当反贝壳结构复合材料基体的应变硬化能力得到提升时,能更好地补偿硬相中裂纹增殖带来的软化效应,复合材料的应变硬化能力得到提升。通过调控反贝壳材料软相片层尺寸,可以实现对拉伸性能的调控。软相片层较大时,材料拥有更好的韧性;软相片层较小时,材料拥有更高的强度。反贝壳结构复合材料良好的强韧性与其结构特点密不可分,其连续的硬相很好地起到了承载作用,而弥散的软相片层则有助于提升复合材料的韧性。该材料的主要强化机制包括弥散强化、细晶强化与异构形变诱导强化,而韧性的提高则归功于软相片层诱导的裂纹钝化和偏转。
SiC/AZ31 inverse nacre structured composite was prepared by mechanical ball milling and thermal deformation,and the microstructure of the composite was effectively controlled by process control.The microstructure was characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM),the mechanical properties of the material were tested by quasi-static tensile test,and the strengthening and toughening mechanism and failure mechanism were preliminarily analyzed by combining the microstructure.The results show that the inverse nacre structure obtained by hot deformation process can significantly improve the tensile properties.When the strain hardening ability of the matrix in the inverse nacre structured composite is improved,it can better compensate for the softening effect caused by crack propagation in the hard phase,and the strain hardening ability of the composite is improved.The tensile properties can be controlled by adjusting the size of the lamellar soft phase in the inverse nacre structured composite.When the size of lamellar soft phase is large,the composite has better toughness.When the size of lamellar soft phase is small,the composite has higher strength.The excellent strength and toughness of the inverse nacre structure composite are arising from its structural characteristics,and the continuous hard phase plays a good role in bearing,while the dispersed lamellar soft phase benefits for improving the toughness of the composite.The main strengthening mechanisms of this material include dispersion strengthening,fine grain strengthening,and heterogeneous deformation induced strengthening,and the improvement of toughness are attributed to the crack blunting and deflection induced by lamellar soft phase.In summary,the architecture design of inverse nacre structure is an effective way to obtain high-strength and tough magnesium matrix composite.
作者
何博
罗茜
常超
赵科
刘金铃
HE Bo;LUO Xi;CHANG Chao;ZHAO Ke;LIU Jinling(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 611756,China;Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province,Southwest Jiaotong University,Chengdu 611756,China)
出处
《航空材料学报》
CAS
CSCD
北大核心
2023年第5期10-19,共10页
Journal of Aeronautical Materials
基金
国家自然科学基金项目(51871187)。
关键词
镁基纳米复合材料
贝壳
构型
强度
韧性
magnesium matrix nanocomposites
nacre
architecture
strength
toughness
