The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E ...The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.展开更多
为了研究Mg_(97)Gd_(2)Y_(1)合金中β'相的粗化过程以及相关析出结构的形成和演变机制,使用原子分辨的高角度环形暗场-扫描透射电子显微镜(high angle annular dark field scanning transmission electron microscope,HAADF-STEM)...为了研究Mg_(97)Gd_(2)Y_(1)合金中β'相的粗化过程以及相关析出结构的形成和演变机制,使用原子分辨的高角度环形暗场-扫描透射电子显微镜(high angle annular dark field scanning transmission electron microscope,HAADF-STEM)成像技术表征了合金不同时效阶段形成的析出结构,并结合第一性原理计算的方法分析了它们的稳定性.结果表明,相关的β_(F)'、β_(M)和β″相主要在β'相粗化过程的早期形成,它们的形成与β'相相界面周围存在较高的错配应变场密切相关;随着β'相粗化过程的进行,β_(M)和β″相的尺寸和数量逐渐减少,而由β'与β_(F)'相交替组成的竹节状析出物增多,成为合金基体中主要的析出结构;当错配应变足够大时,β_(F)'相内部出现位错,β相在位错处可以形核,并逐渐长大成为基体中主要的平衡析出结构.展开更多
文摘The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.
文摘为了研究Mg_(97)Gd_(2)Y_(1)合金中β'相的粗化过程以及相关析出结构的形成和演变机制,使用原子分辨的高角度环形暗场-扫描透射电子显微镜(high angle annular dark field scanning transmission electron microscope,HAADF-STEM)成像技术表征了合金不同时效阶段形成的析出结构,并结合第一性原理计算的方法分析了它们的稳定性.结果表明,相关的β_(F)'、β_(M)和β″相主要在β'相粗化过程的早期形成,它们的形成与β'相相界面周围存在较高的错配应变场密切相关;随着β'相粗化过程的进行,β_(M)和β″相的尺寸和数量逐渐减少,而由β'与β_(F)'相交替组成的竹节状析出物增多,成为合金基体中主要的析出结构;当错配应变足够大时,β_(F)'相内部出现位错,β相在位错处可以形核,并逐渐长大成为基体中主要的平衡析出结构.
