【摘要】 通过显微硬度和抗拉强度试验、X射线衍射仪、扫描电镜和金相显微镜观察,研究经旋转摩擦挤压法制备的CNTs/Mg复合材料的组织及性能。结果表明:CNTs/Mg复合材料的组织为细小等轴晶,且随着CNTs含量的增加,复合材料晶粒尺寸逐渐细化,当CNTs含量为5%时,晶粒尺寸最小,由63μm减小至3.79μm,为AZ91基材晶粒尺寸的6.01%。经过旋转摩擦挤压加工后基材内第二相β-Al12Mg17相的量减少,CNTs的加入使复合材料中出现了Al4C3相,且第二相β-Al12Mg17相网状结构消失。加工后的镁合金抗拉强度提高,最大值为330.9 MPa,较原基材提高了90.6%,当CNTs含量小于2%时,复合材料强度高于原基材。复合材料硬度随着CNTs含量的增加呈先增加后降低的趋势,当CNTs含量为2%时,硬度最高,达101.3HV,比AZ91基材提高了40.3%。更多还原

【Abstract】 The microstructure and properties of carbon nanotubes reinforced magnesium(CNTs/Mg)composites fabricated by rotational friction extrusion were studied by the hardness and tensile strength test,X-ray diffraction,scanning electron microscopy and optical microscopy.The results show that the microstructure of CNTs/Mg composites is fine equiaxed grains,and with the increase of CNTs,the grain size gradually refined.When the content of CNTs is 5%,the composites obtain the minimum grain size which decreases from 63μm to 3.79μm,accounting for 6.01% of AZ91 matrix.The second phaseβ-Al12Mg17 phase of AZ91 matrix decreases after rotational friction extrusion processing,Al4C3 comes up and the network structure of the second phaseβ-Al12Mg17 phase disappear.The tensile strength of magnesium alloy increase after processing,the maximum value of 330.9 MPa,compared with the original substrate increased by 90.6%,when the CNTs content of less than 2%,the composite strength higher than the original substrate.The hardness of the composites first increases and then decrease.When the content of CNTs is 2%,the hardness is 101.3HV,which is 40.3% higher than AZ91 matrix.更多还原