Annealing effects of high sensitive thin strain gauges consisting of nickel carbon nanocomposites

2018 ◽  
Vol 37 (22) ◽  
pp. 1378-1384 ◽  
Author(s):  
Christos Karapepas ◽  
Daisy Nestler ◽  
Daniel Wett ◽  
Guntram Wagner

Hybrid laminates consisting of fiber-reinforced thermoplastic films and metallic thin sheets are successively replacing thermoset-based systems due to their obvious advantages of higher formability and the aptitude for mass production. In order to monitor the material under operating condition, hybrid laminates need to be equipped with smart sensor units. Therefore, the aim of the present work is to evaluate the temperature stability of the Ni-C thin film strain gauge sensors. The analyses of the deposited Ni-C films manufactured by means of a magnetron sputtering process were carried out by means of Raman spectroscopy and X-ray diffraction to investigate the phase development after a heat treatment at different temperatures and holding times. In addition, the four-terminal sensing was utilized to study the change of temperature coefficients of resistance after a single annealing treatment.

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 858
Author(s):  
Shenglin Liu ◽  
Yongsheng Zhu ◽  
Xinyue Lai ◽  
Xueping Zheng ◽  
Runnan Jia ◽  
...  

Fe-based amorphous/nanocrystalline coatings with smooth, compact interior structure and low porosity were fabricated via supersonic plasma spraying (SPS). The coatings showed outstanding corrosion resistance in a 3.5% NaCl solution at room temperature. In order to analyze the effect of annealing treatment on the microstructure, corrosion resistance and microhardness, the as-sprayed coating was annealed for 1 h under different temperatures such as 350, 450, 550 and 650 °C, respectively. The results showed that the number of oxides and cracks in the coatings presented an obvious increase with increasing annealing temperature, and the corrosion resistance of the coatings showed an obvious reduction. However, the microhardness of coatings showed an important increase. The microhardness of the coating could reach 1018 HV when the heat treatment temperature reached 650 °C. The X-ray diffraction (XRD) results showed that there appeared a number of crystalline phases in the coating when the heat treatment temperature was at 650 °C. The crystalline phases led to the increase of the microhardness.


1998 ◽  
Vol 13 (5) ◽  
pp. 1198-1203 ◽  
Author(s):  
K. W. Liu ◽  
J. S. Zhang ◽  
J. G. Wang ◽  
G. L. Chen

Formation of nanocrystalline Al3Ti, TiAl, Ti3Al, and Ti5Si3 composites by mechanically alloying (MA) in the Ti–Al–Si system and subsequent annealing treatment are investigated. Microstructure development was monitored by x-ray diffraction, differential thermal analysis, and transmission electron microscopy. An amorphous phase could be generated through milling for 100 h. The results of annealing at different temperatures on this amorphous phase show that the formation of titanium aluminides (Al3Ti, TiAl, and Ti3Al, according to the initial relative amount of Ti and Al) and Ti5Si3 (the only silicide produced by the crystallization reaction) take place. Annealing produces nanocrystalline composites of Al3Ti, TiAl, Ti3Al, and Ti5Si3 with a grain size less than 20 nm. With increasing annealing temperature, the crystalline sizes of the phases increased.


Author(s):  
Wei Ren ◽  
Guang-Dao Yang ◽  
Ai-Ling Feng ◽  
Rui-Xia Miao ◽  
Jun-Bo Xia ◽  
...  

AbstractTantalum pentoxide (Ta2O5) has attracted intensive attention due to their excellent physicochemical properties. Ta2O5 films were synthesized via electron beam evaporation (EBE) and subsequently annealed at different temperatures ranging from 300 to 900 °C. X-ray diffraction (XRD) results show that amorphous Ta2O5 thin films form from 300 to 700 °C and then a phase transition to polycrystalline β-Ta2O5 films occurs since 900 °C. The surface morphology of the Ta2O5 films is uniform and smooth. The resulted Ta2O5 films exhibit excellent transmittance properties for wavelengths ranging from 300 to 1100 nm. The bandgap of the Ta2O5 films is broadened from 4.32 to 4.46 eV by annealing. The 900 °C polycrystalline film electrode has improved electrochemical stability, compared to the other amorphous counterparts.


1995 ◽  
Vol 10 (5) ◽  
pp. 1247-1255 ◽  
Author(s):  
K.Y. Wang ◽  
J.G. Wang ◽  
G.L. Chen

Formation of nanocrystalline composites γ-TiAl + Ti2AlN by mechanically alloying (MA) Ti50Al50 in a N2 atmosphere and subsequent annealing treatment are investigated. The development of the microstructure was monitored by x-ray diffraction, and differential thermal analysis and transmission electron microscopy. The amorphous phase could be obtained after milling for 30 h in a nitrogen atmosphere. The TEM results show that some nanocrystalline solid solution of Al in Ti also existed in the amorphous matrix. The results of annealing treatments at different temperatures for 0.5 h on the amorphous phase obtained by MA in N2 gas for 30 h show the formation of γ-phase (TiAl) and a nitride of titanium and aluminum (Ti2AlN). Available annealing treatments could produced nanocrystalline composites of γ-TiAl and Ti2AlN with a grain size less than 20 nm. With increasing annealing temperature, the crystalline sizes of γ-TiAl and Ti2AlN increase, but the values of microhardness increase slightly.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3103
Author(s):  
Laurent Gremillard ◽  
Agnès Mattlet ◽  
Alexandre Mathevon ◽  
Damien Fabrègue ◽  
Bruno Zberg ◽  
...  

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).


2000 ◽  
Vol 655 ◽  
Author(s):  
Jung-Hyuk Koh ◽  
S.I. Khartsev ◽  
Alex Grishin ◽  
Vladimir Petrovsky

AbstractFor the first time AgTa0.38Nb0.62O3 (ATN) films have been grown on the La0.7Sr0.3CoO3 (LSCO)/LaAlO3 single crystal as well as onto Pt80Ir20 (PtIr) polycrystalline substrate. Comprehensive X-ray diffraction analyses reveal epitaxial quality of ATN and LSCO films on the LaAlO3(001) substrate, while ATN/PtIr films have been found to be (001) preferentially oriented. Dielectric spectroscopy performed for ATN films and bulk ceramics in a wide temperature range 77 to 420 K shows the structural monoclinic M1-to-monoclinic M2 phase transition occurs in films at the temperature 60 °C lower than in ceramics. The tracing of the ferroelectric hysteresis P-E loops indicates the ferroelectric state in ATN films at temperatures below 125 K and yields remnant polarization of 0.4 μC/cm2 @ 77 K. Weak frequency dispersion, high temperature stability of dielectric properties as well as low processing temperature of 550 °C make ATN films to be attractive for various applications.


2016 ◽  
Vol 675-676 ◽  
pp. 573-576 ◽  
Author(s):  
Pratya Thongpanit ◽  
Weerapong Chewpraditkul ◽  
Nakarin Pattanaboonmee

Ammonium dihydrogen phosphate (ADP) crystals is very interesting due to its nonlinear optical property. This study investigated on improving of material for academic use by adding boric acid to modify ADP crystals. Slow evaporation method in aqueous solutions of pure ADP and ADP doped with three concentrations of H3BO3 as 0.1, 1.0, 5.0 %wt were studied. The grown crystals were confirmed tetragonal structure by powder X-ray diffraction studies. The FTIR spectrum analysis presented various functional groups of boron in three conditions of doped ADP. TGA study was comfirned the temperature stability at 220 °C for both pure and doped ADP crytals. The machanical stress was analyzed by Vicker’s hardness measurement. The results of this analysis showed boric acid doped 1.0 %wt had superior machanical stress from 10 to 75 grams. ADP doped with boric acid at 1.0 %wt was accepted in all test properties.


2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.


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