APPLICATION OF ESR TO HIGH-Tc SUPERCONDUCTORS AND RELATED MATERIALS III: CRYSTAL GROWTH RATES OF Y2BaCuO5 IN THE MELTS OF Y1+2nBa2+nCu3+nOx (n=0–0.4) SUBJECTED TO HIGH TEMPERATURES

1999 ◽  
Vol 13 (02) ◽  
pp. 51-58 ◽  
Author(s):  
K. YAMAMOTO ◽  
N. ARAI ◽  
K. HOTTA ◽  
K. SUGAWARA ◽  
H. HIROSE

Form the ESR measurements of Cu 2+ in Y 2 BaCuCuO 5, the growth rates of Y 2 BaCuCO 5 generated in the melts of Y 1+2n Ba 2+n Cu 3+n O x (n=0–0.4) have been quantitatively obtained as functions of heat-treatment temperature (1000–1400°C) and heat-treatment period (10–120 minutes). All the melted samples have been prepared by heating them in an atmospheric condition, and room-temperature quenching.

1999 ◽  
Vol 13 (02) ◽  
pp. 43-50
Author(s):  
K. YAMAMOTO ◽  
S. KAWASHIMA ◽  
K. HOTTA ◽  
K. SUGAWARA ◽  
H. HIROSE

The effects of heat-treatment temperature (HTT) and heat-treatment period (HTP) on the growth rates of Y 2 BaCuO 5 in the melts with nominal composition of Y: Ba : Cu = 1.8 : 2.4 : 3.4 have been investigated. The ranges of HTT and HTP are 1000~1400° C and 1~120 minutes, respectively. The quantities of Cu 2+ in Y 2 BaCuO 5 have been obtained by ESR, and its growth rates in the aforementioned melts have been quantitatively measured as functions of HTT and HTP.


1998 ◽  
Vol 12 (10) ◽  
pp. 363-370 ◽  
Author(s):  
K. Yamamoto ◽  
N. Arai ◽  
K. Hotta ◽  
K. Sugawara ◽  
H. Hirose

A number of pellets with nominal concentration ratio of Y:Ba:Cu =2:1:1 have been sintered in air at temperatures between 800°C and 1400°C for 1 min ~24 h. The heat-treated samples were quenched to room temperature and the crystal growth rates of Y 2 BaCuO y≃5 were measured using ESR of Cu 2+. Systematic data on the growth rates were taken as a function of heat-treatment temperature and period.


2019 ◽  
Vol 15 ◽  
pp. 102569
Author(s):  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Sidek Hj Ab Aziz ◽  
Halimah Mohamed Kamari ◽  
Yap Wing Fen ◽  
...  

2018 ◽  
Vol 281 ◽  
pp. 959-963
Author(s):  
Feng Zhang ◽  
Chuan Qi Hu ◽  
Shi Chao Zhang ◽  
Hao Ran Sun ◽  
Yuan Tian ◽  
...  

In this paper, the modified phenolic resin-based adhesive was prepared by dissolving different components. After low temperature curing, SiC samples were bonded by the binder. The samples were treated at different temperatures (400°C, 800°C, 1200°C, 1500°C) under an inert atmosphere. The bonding strength of samples was tested after heat treatment at room temperature. The results showed that the bonding strength of the B4C modified phenolic resin (PF) based adhesive is the highest. When the heat treatment temperature was above 1200°C, the bond strength increased with the additive amount of boron carbide at room temperature. The microstructures of the samples were observed by optical microscope and scanning electron microscope. The effects of the modified filler and heat treatment temperature on the bonding strength of the phenolic resin based adhesive were investigated. The bonding strength of boron carbide-modified phenolic resin-based binder was tested under high temperature. It was found that the bond strength at high temperature was lower than that at room temperature, and the bond strength decreased with the increase of temperature.


2018 ◽  
Vol 941 ◽  
pp. 1366-1371
Author(s):  
Masahiro Sakata ◽  
Jong Yeong Oh ◽  
Ken Cho ◽  
Hiroyuki Y. Yasuda ◽  
Mitsuharu Todai ◽  
...  

In the present study, effects of heat treatment on microstructures and tensile properties of the cylindrical bars of Ti-48Al-2Cr-2Nb (at.%) alloy with unique layered microstructure consisting of equiaxed γ grains region (γ band) and duplex-like region fabricated by electron beam melting (EBM) were investigated. We found that it is possible to control width of the γ bands (Wγ) by heat treatments at 1100°C and 1190°C. The Wγ increases with decreasing heat treatment temperature. The bars heat-treated at 1190°C exhibit high elongation of 2.9% at room temperature (RT) with maintaining high strength. The RT elongation increases with increasing the Wγ because of increasing deformable regions. In contrast, the RT elongation of the bars decreases with increasing the Wγ when Wγ is very large. This is because the large γ band leads intergranular fracture. These results indicate that there is appropriate width for the γ band to obtain excellent tensile properties at RT.


2017 ◽  
Vol 18 (1) ◽  
pp. 69-74
Author(s):  
Leandro Voisin ◽  
Makoto Ohtsuka ◽  
Takashi Nakamura ◽  
S. Petrovska ◽  
B. Ilkiv ◽  
...  

Indium saving indium tin oxide ITO thin films have been deposited using a sputtering deposition technique in pure Ar and in mixed argon-oxygen atmosphere at room temperature. A transmittance value of more than 85 % in the visible region of the spectrum and a resistivity of 2420 µΩcm has been obtained for the thin films deposited in pure Ar and subsequently heat treated at 923 K. The structure of the as-deposited indium saving indium-tin oxide films was amorphous and the crystallinity was improved with increasing heat treatment temperature. An increase in the heat treatment temperature does not enhance the transmittance of the films at oxygen flow rate higher than 0.4 cm3/min.


2016 ◽  
Vol 879 ◽  
pp. 1036-1042 ◽  
Author(s):  
Manoj Kumar ◽  
Georg Kirov ◽  
Florian Grabner ◽  
Ermal Mukeli

High strength AW-7xxx sheet alloys are promising candidates to manufacture crash relevant parts, but their limited formability at room temperature presents a major challenge. Formability is controlled through heating rate, heat treatment temperature and time, quenching rate, forming temperature and strain rate. In the literature retrogression forming, W-temper forming, warm forming and hot stamping processes have been proposed to improve the formability of AW-7xxx alloys. Of these the greatest improvement in formability comes from W-temper forming and hot stamping. Considering the similarity to the conventional forming processes of cold stamping for aluminium and hot stamping for steel, the W-temper forming and hot stamping of aluminium are promising for AW-7xxx alloys.


1991 ◽  
Vol 246 ◽  
Author(s):  
Ming-Yuan Kao ◽  
Sepehr Fariabi ◽  
Paul E. Thoma ◽  
Husnu Ozkan ◽  
Louis Cartz

AbstractThe reversible transformations between the Austenite (A) and Martensite (M) phases of NITI shape memory wires having a 78°C austenlte finish temperature (950°C annealed) were studied In the cold work and heat treatment ranges between 14 to 62% and 400 to 525°C respectively. The ranges of peak Transformation Temperatures (TI), determined by Differential Scanning Calorimetry (DSC) at a 10°C/min rate, were found to be 56 to 75°C, -28 to 33°C, and 38 to 52°C for the respective high temperature A, low temperature M, and the Intermediate Rhombohedral (R) phases. The degree of cold work and heat treatment had significant effects on the TT of NITI wires. The peak TT of A and M decreases with Increasing cold work. Except for the 14% cold worked wires, the peak TT Increases with Increasing heat treatment temperature for M, and Increases with Increasing heat treatment temperature for A for temperatures higher than 450°C. The peak IT of R Increases with Increasing cold work and decreasing heat treat temperature.Using MoKα radiation, transmission x-ray diffraction analysis was utilized to determine the phases at room temperature on wires thinned down to 0.05 to 0.01 mm in diameter. The diffraction patterns of body-centered cubic austenite (132) and monodlinic martenslte (B19) for NITi were both Identified. In addition, extra diffraction lines observed for various samples were tentatively assigned to M and the Intermediate R-phase. Depending on the thermal history and the processing conditions, the NITI wires consist of either a pure M, a mixture of A and R, or a mixture of A, R, and M at room temperature.


2013 ◽  
Vol 27 (10) ◽  
pp. 1079-1083
Author(s):  
Zhao-Hui LIU ◽  
Gen-Liang HOU ◽  
Xun-Jia SU ◽  
Feng GUO ◽  
Zhou XIAO ◽  
...  

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