Ba[(Zn_(1-x)Mg_x)_(1/3)Ta(2/3)]O_3(BZMT,x=0,0.2,0.4,0.6,0.8,and 1.0)solid solution ceramics were synthesized by a conventional solid-state sintering technique.Vibration spectra(Raman spectroscopy and Fourier trans for...Ba[(Zn_(1-x)Mg_x)_(1/3)Ta(2/3)]O_3(BZMT,x=0,0.2,0.4,0.6,0.8,and 1.0)solid solution ceramics were synthesized by a conventional solid-state sintering technique.Vibration spectra(Raman spectroscopy and Fourier trans form far-infrared reflection spectroscopy)and X-ray diffraction(XRD)were employed to evaluate the correla tion between microstructures and phonon modes of these solid solutions.Spectroscopic and structural data show sensitivity to structural evolution of samples with Mg^(2+)concentration,and a 1:2 ordered phase appears when x≥0.2.The unit cell parameters decrease with increasing Mg^(2+)content.The ordering degree reaches a relative maximum value in the range of Mg^(2+)content,0.4≤x<0.6.The phonon modes were assigned,and the correlation of phonon vibrations in the microstructure were analyzed.The position and width of the phonon modes were determined and correlated to the ionic radii for the different atoms substituted in the B'-site.展开更多
Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SE...Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SEM)technologies,respectively.Lattice vibrational modes展开更多
Hypersonic vehicles and aircraft engine blades face complex and harsh environments such as high heat flow density and high temperature,and they are generally narrow curved spaces,making it impossible to actually insta...Hypersonic vehicles and aircraft engine blades face complex and harsh environments such as high heat flow density and high temperature,and they are generally narrow curved spaces,making it impossible to actually install them for testing.Thin-film heat flux sensors(HFSs)have the advantages of small size,fast response,and in-situ fabrication,but they are prone to reach thermal equilibrium and thus fail during testing.In our manuscript,an ITO–In_(2)O_(3)thick film heat flux sensor(HFS)is designed,and a high-temperature heat flux test system is built to simulate the working condition of a blade subjected to heat flow impact.The simulation and test results show that the test performance of the thick-film HFS is improved by optimizing the structure and parameters.Under the condition of no water cooling,the designed HFS can realize short-time heat flux monitoring at 1450℃and long-term stable monitoring at 1300℃and below.With a maximum output thermopotential of 17.8 mV and an average test sensitivity of 0.035 mV/(kW/m^(2)),the designed HFS has superior high-temperature resistance that cannot be achieved by other existing thin(thick)film HFSs.Therefore,the designed HFS has great potential for application in harsh environments such as aerospace,weaponry,and industrial metallurgy.展开更多
文摘Ba[(Zn_(1-x)Mg_x)_(1/3)Ta(2/3)]O_3(BZMT,x=0,0.2,0.4,0.6,0.8,and 1.0)solid solution ceramics were synthesized by a conventional solid-state sintering technique.Vibration spectra(Raman spectroscopy and Fourier trans form far-infrared reflection spectroscopy)and X-ray diffraction(XRD)were employed to evaluate the correla tion between microstructures and phonon modes of these solid solutions.Spectroscopic and structural data show sensitivity to structural evolution of samples with Mg^(2+)concentration,and a 1:2 ordered phase appears when x≥0.2.The unit cell parameters decrease with increasing Mg^(2+)content.The ordering degree reaches a relative maximum value in the range of Mg^(2+)content,0.4≤x<0.6.The phonon modes were assigned,and the correlation of phonon vibrations in the microstructure were analyzed.The position and width of the phonon modes were determined and correlated to the ionic radii for the different atoms substituted in the B'-site.
文摘Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SEM)technologies,respectively.Lattice vibrational modes
基金supported in part by the National Nature Science Foundation of China under Grant 52175525in part by the National Key Research and Development Program of China under Grant 2020YFB2009100(104)+1 种基金in part by the Innovative Research Group Project of the National Natural Science Foundation of China under Grant 51821003in part by the Fund for Shanxi‘1331 Project’Key Subject Construction.
文摘Hypersonic vehicles and aircraft engine blades face complex and harsh environments such as high heat flow density and high temperature,and they are generally narrow curved spaces,making it impossible to actually install them for testing.Thin-film heat flux sensors(HFSs)have the advantages of small size,fast response,and in-situ fabrication,but they are prone to reach thermal equilibrium and thus fail during testing.In our manuscript,an ITO–In_(2)O_(3)thick film heat flux sensor(HFS)is designed,and a high-temperature heat flux test system is built to simulate the working condition of a blade subjected to heat flow impact.The simulation and test results show that the test performance of the thick-film HFS is improved by optimizing the structure and parameters.Under the condition of no water cooling,the designed HFS can realize short-time heat flux monitoring at 1450℃and long-term stable monitoring at 1300℃and below.With a maximum output thermopotential of 17.8 mV and an average test sensitivity of 0.035 mV/(kW/m^(2)),the designed HFS has superior high-temperature resistance that cannot be achieved by other existing thin(thick)film HFSs.Therefore,the designed HFS has great potential for application in harsh environments such as aerospace,weaponry,and industrial metallurgy.
