碳纤维与扩散层厚度对Al-Mg-Ti微叠层复合材料组织性能的影响

Effect of carbon fiber and diffusion layer thickness on tissue properties of Al-Mg-Ti laminated composites

以1060纯铝、TC4钛合金、AZ31镁合金和镀镍碳纤维编织布为原材料,使用真空热压扩散技术和“箔-纤维-箔”法制备出碳纤维增强Al-Mg-Ti微叠层复合材料。通过控制铝镁保温时间分析了铝镁扩散层厚度对材料组织性能的影响,探讨碳纤维的强化机理,采用X射线衍射仪(XRD)、能谱分析仪(EDS)和扫描电子显微镜(SEM)等分析了复合材料的相组成、元素分布与裂纹扩展形貌,测试了复合材料的抗弯强度和冲击韧性。结果表明:碳纤维增强Al-Mg-Ti微叠层复合材料扩散层厚度随着保温时间的延长而增加,力学性能呈先上升后下降的趋势,碳纤维通过纤维脱粘、纤维拔出和纤维劈裂等方式吸收了大量断裂能,起到显著的增韧效果。在铝钛热压温度640℃保温时间2 h,铝镁热压温度440℃保温时间8 h时,复合材料力学性能最优,抗弯强度为380 MPa,冲击韧度为26.2 J/cm^(2),相对于基体抗弯强度和冲击韧性分别提高了10.8%和30.3%。

Carbon fiber-reinforced Al-Mg-Ti laminated composites were prepared by vacuum hot-press diffusion technique and"foil-fiber-foil"method using 1060 pure aluminum,TC4 titanium alloy,AZ31 magnesium alloy and nickel-plated carbon fiber woven fabric as raw materials.The effect of Al-Mg diffusion layer thickness on the material tissue properties was analyzed by controlling the Al-Mg holding time,and the strengthening mechanism of carbon fiber was discussed.The phase composition,element distribution and crack extension morphology of the composites were analyzed by X-ray diffraction(XRD),energy spectrum(EDS)analyzer and scanning electron microscopy(SEM),and the flexural strength and impact toughness of the composites were tested.The results show that the thickness of diffusion layer of carbon fiber-reinforced Al-Mg-Ti laminated composites increases with the increase of holding time,and the mechanical properties show a trend of increasing and then decreasing,and the carbon fiber absorbs a large amount of fracture energy through fiber debonding,fiber pull-out and fiber splitting,which plays a significant toughening effect.The mechanical properties of the composites are optimal at the hot pressing temperature of 640℃ for 2 h for Al-Ti and 440℃ for 8 h for Al-Mg,with flexural strength of 380 MPa and impact toughness of 26.2 J/cm^(2),which are increased by 10.8 %and 30.3% respectively,relative to the matrix flexural strength and impact toughness.