共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Victor T. Witusiewicz Ferdinand Sommer 《Metallurgical and Materials Transactions B》2000,31(2):277-284
The partial (Δ
and the integral (ΔH) enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys have been determined by high-temperature isoperibolic calorimetry
at 1565 ± 5 K. The heat capacity (C
p) of liquid Ni26Zr74 has been measured by adiabatic calorimetry (C
p=53.5±2.2 J mol−1 K−1 at 1261±15 K). The integral enthalpy of mixing changes with composition from a small positive (Cu-Ni, ΔH (x
Ni=0.50, T=1473 to 1750 K)=2.9 kJ mol−1) to a moderate negative (Cu-Zr; ΔH(x
Zr=0.46, T=1485 K)=−16.2 kJ mol−1) and a high negative value (Ni-Zr; ΔH(x
Zr=0.37, T=1565 K)=−45.8 kJ mol−1). Regression analysis of new data, together with the literature data for liquid Ni-Zr alloys, results in the following relationships
in kJ mol−1 (standard states: Cu (1), Ni (1), and Zr (1)):for Ni-Zr (1281≤T≤2270 K),
for Cu-Ni-Zr (T=1565±5 K),
相似文献
14.
15.
Joo Hyun Park Sang-Beom Lee Henri R. Gaye 《Metallurgical and Materials Transactions B》2008,39(6):853-861
16.
Interdiffusion coefficients in Nb2C and NbC1−x were measured using bulk diffusion couples in the temperature range from 1400 °C to 1700 °C. Marker experiments were used
to show that carbon is the only component undergoing significant diffusion in both carbides. Carbon concentrations were measured
by difference using electron probe microanalysis, and interdiffusion coefficients were taken from Boltzmann-Matano analyses
of the resulting concentration profiles. This analysis clearly showed that, in NbC1−x, interdiffusion coefficient varies with carbon concentration, and is expressed by
where x is the site fraction of vacancies on the carbon sublattice. The interdiffusion coefficient in Nb2C is given by
Parabolic layer growth coefficients were estimated from the Nb|C diffusion couples as well. They are given by
The value of
in NbC1−x was found to be consistent with literature values for the tracer diffusivity of C in NbC1−x
via the thermodynamic factor, which was determined in two ways. 相似文献
17.
The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace using
a vapor-liquid equilibration method. A sealed Mo reaction chamber and a self-made CaO crucible were used in this study. The
thermodynamic parameters obtained are as follows.
For reaction Ca (g)=[Ca],
The relation between dissolved calcium in liquid iron and calcium vapor can be expressed as
The interaction parameters of third elements on calcium determined at 1873 K are as follows:
相似文献
18.
19.
Hiroaki Yamamoto Masao Morishita Akio Miyata Koichiro Koyama 《Metallurgical and Materials Transactions B》2006,37(4):607-613
The standard Gibbs energies of formation of Ni3B, Ni2B, o-Ni4B3(Ni0.586B0.414), m-Ni4B3(Ni0.564B0.436), NiB, and Ni3B2O6 of the Ni-B-O system have been determined by measuring electromotive forces of galvanic cells using a Y2O3-stabilized ZrO2 solid oxide electrolyte. The results are as follows:
Temperature range: 1198 to 1298 K
Temperature range: 1182 to 1285 K
Temperature range: 1193 to 1273 K
Temperature range: 1193 to 1273 K
Temperature range: 1203 to 1253 K
Temperature range: 1182 to 1393 K where the standard pressure is 1 bar (100 kPa). 相似文献
20.
S. Hata T. Nakano N. Kuwano M. Itakura S. Matsumura Y. Umakoshi 《Metallurgical and Materials Transactions A》2008,39(7):1610-1617
The ordering mechanism of long-period superstructures (LPSs) in Al-rich TiAl alloys has been investigated by high-resolution
transmission electron microscopy (HRTEM). The LPSs are classified in terms of arrangements of base clusters with different
shapes and compositions formed in Ti-rich (002) layers of L10-TiAl matrix: square Ti4Al, fat rhombus Ti3Al, and lean rhombus Ti2Al type clusters. The HRTEM observations revealed that antiphase boundaries of long-range-ordered LPS domains and short-range-ordered
microdomains are constructed by various space-filling arrangements of the base clusters. Such a microscopic property characterized
by the base clusters and their arrangements is markedly analogous to that of the
* special-point ordering alloys such as Ni-Mo.
This article is based on a presentation given in the symposium entitled “Materials Behavior: Far from Equilibrium” as part
of the Golden Jubilee Celebration of Bhabha Atomic Research Centre, which occurred December 15–16, 2006 in Mumbai, India.
相似文献
S. Hata (Associate Professor)Email: |