【摘要】 本研究以高纯W与Al₂O₃为靶材,在常温下采用磁控溅射法在钠钙硅玻璃表面交替镀制了W及Al₂O₃纳米多层膜。在多层膜总厚度相同的条件下,研究了不同W/Al₂O₃周期厚度对隔热性能的影响。采用台阶仪、扫描电镜（SEM）、X射线衍射仪（XRD）、场发射透射电镜（TEM）等对多层膜的形貌及结构进行了表征。采用瞬态热反射法（TTR）、纳米压痕仪分别分析了多层膜的隔热性能和力学性能。结果表明,实验沉积的多层膜中各单层均匀连续,不存在断层现象,且层间界面清晰。Al₂O₃膜层呈非晶形态,W膜层具有亚稳态β-W（210）的择优取向,并在周期厚度为5 nm时呈现明显的非晶态。随着膜层界面密度的增大,多层膜的热阻增大,热导率减小,硬度增大。周期厚度为5 nm、膜层数为41层的W/Al₂O₃多层膜具有较为优异的隔热性能与力学性能,其热阻为3. 14×10-7m²·K·W^-1,有效热导率为0. 36 W·m-1·K-1,硬度为8. 53 GPa,膜/基结合力为42. 20m N。所制备的多层膜在室温到500℃之间具有良好的热稳定性。更多还原

【Abstract】 This work carried out an alternative deposition of W/Al₂O₃ nano-multilayers with various periodic thickness on the surface of soda-lime-silica glass by means of magnetron sputtering at room temperature,taking W and Al₂O₃ as targets. Under the condition of the same total thickness of W/Al₂O₃ nano-multilayers,the effects of various periodic thickness on thermal insulation performance of W/Al₂O₃ were investigated. Step profiler,scanning electron microscope（SEM）,X-ray diffraction（XRD） and transmission electron microscope（TEM） were employed to characterize the morphology and structure of W/Al₂O₃ nano-multilayers. Transient thermoreflectance（TTR） technique and nano indentation instrument were adopted to measure the thermal and mechanical properties of W/Al₂O₃ nano-multilayers. It was found that the individual layer in the nano-multilayers was uniform and continuous,no fault could be observed and interface between the layers was clear. The deposited Al₂O₃ layer exhibited an amorphous morphology,and the W layer held a metastable β-W（210） preferred orientation and showed an obvious amorphous state under the periodic thickness of 5 nm. The increase of interface density would bring about the enhancement in thermal resistance and hardness,and the decline in thermal conductivity of W/Al₂O₃ nano-multilayers. The W/Al₂O₃ nano-multilayers with 41 layers and periodic thickness of 5 nm exhibited an exceptional thermal insulation and mechanical properties,presenting the thermal resistance of 3. 14×10-7 m²·K·W^-1,effective thermal conductivity of 0. 36 W·m-1·K-1,hardness up to 8. 53 GPa,binding force between multilayers and substrate of 42. 20 m N. The prepared W/Al₂O₃ nano-multilayers possess a satisfactory thermal stability in the range of room temperature to 500 ℃.更多还原