共查询到20条相似文献,搜索用时 46 毫秒
1.
The compression properties of Zr41Ti14Cu12.aNi10Be22.5, Zr44.4Nb7Cu13.5Ni10.8Be24.3 bulk metallic glasses and Ni77P23 binary amorphous alloy are investigated at room temperature up to 24 GPa, 39 GPa and 30.5 GPa, respectively, using in-situ high pressure energy dispersive x-ray diffraction with a synchrotron radiation source. The pressure-volume relationship of Ni77P23 amorphous alloy is consistent well with the second order BirchMurnaghan (B-M) equation within the experimental pressure range. However, under higher pressure, the experimental data of Zr-based specimens deviate from the B-M equation. Compare to the binary amorphous alloy less excess free volume existing in the bulk metallic glass and multi-component atomic configuration results in a two-stage relationship between compressibility and pressure. 相似文献
2.
利用同步辐射高能X光散射的方法,研究了室温下非晶合金Ni77P23的自由体积的变化所引起的压缩行为的变化规律,通过傅里叶变换得到不同压力下的径向分布函数,并由此获得了不同压力下,该非晶合金的配位数、近邻原子间距等原子构型的结构信息. 研究表明,至直30.5GPa压力,Ni77P23合金仍保持稳定的非晶结构,根据Bridgman方程通过拟合数据,得到状态方程为-ΔV/V0=0.08606P-3.2×10-4P2+5.7×10-6P3.
关键词:
非晶合金
自由体积
同步辐射 相似文献
3.
4.
利用正电子湮没技术(PAT)测量了不同化学计量比二元Ni33Al合金及不同Zr含 量Ni33Al合金的正电子寿命谱,并估算了合金基体和晶界缺陷处的自由电子密度.结果表明,二元Ni7777Al2323合金的基体和缺陷态的自由电子密度都比二元 Ni7474Al2626合金的高. Ni33Al合金晶界缺陷处开空间大于Ni空位或Al空位的开空间,晶界缺 陷处的自
关键词:
3Al合金')" href="#">Ni33Al合金
微观机制
自由电子密度
韧化 相似文献
5.
本文研究了Fe40Ni40P12B8非晶合金冲击波加载下的晶化行为,冲击波由二级轻气炮发射的告诉弹丸撞击靶产生。实验结果表明:Fe40Ni40P12B8非晶合金在冲击波加载下,晶化可在加载时间(微秒量级)内发生;晶化的阈值压力在30~50 GPa之间,相应的冲击温度约为510~800 K,晶化析出相与冲击压力有关,低压下析出相是面心立方γ-(Fe, Ni)固溶体和Fe3(P0.37B0.63)化合物,高压下(大于60 GPa)析出相除了面心立方γ-(Fe, Ni)固溶体和Fe3(P0.37B0.63)化合物之外,还包括(Fe, Ni)3P化合物。 相似文献
6.
7.
In a previous work [1], a large magnetic anisotropy was found as a preliminary result of the formation of electrochemically deposited Fe93P7 alloy. Mössbauer spectroscopy was used in order to get information about the magnetic anisotropy of electrochemically prepared Fe?P and Fe?Ni?P amorphous alloys. The Mössbauer spectra and the hyperfine field distributions of the samples show that Fe?Ni?P and Fe?P electrodeposited amorphous materials can be prepared in a reproducible way from a point of view of short range ordering which is strongly dependent on the chemical composition determined by preparation conditions. The average magnetization directions in the samples were determined from the transmission spectra measured in a normal and two tilted geometries by two types of evaluation methods [2,3]. We have found that the small spread model of the domain structure better describes the experimental results. The obtained data reflect the prevailing anomalous magnetization orientation in these electrodeposited amorphous alloys. 相似文献
8.
9.
采用分子动力学模拟的方法研究了Cu50Ni50合金在不同冷却速度下的凝固过程,利用均方位移、径向分布函数和结构可视化等方法分析其微观结构.并对凝固模型进行拉伸模拟,通过应力应变曲线和直观结构变化分析其性能.研究表明:冷却速度对Cu50Ni50合金凝固形成的结构有较大影响,随着冷却速度的升高,凝固形成的结构中晶体含量减少,在较低的冷却速度下,如冷却1×1012K/s时,Cu50Ni50合金凝固形成晶体结构;在较高的冷却速度下,如1×1014K/s时,Cu50Ni50合金凝固形成非晶体结构,且非晶Cu50Ni50合金的抗拉性能要优于晶体Cu50Ni50合金. 相似文献
10.
11.
《中国科学:物理学 力学 天文学(英文版)》2010,(12)
Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti stainless steel. Its weight loss result measured in 2 mol/L HCl solution is in agreement with the potentiodynamic curve. But there is no obvious difference in the oxidation resistances between Zr 60 Ni 21 Al 19 amorphous and its crystalline alloys. They both exhibit high oxidation resistance. 相似文献
12.
Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) are employed to investigate the effects of nickel on the crystallization of the amorphous Zr70Cu20Ni10 alloy. We have found that the crystallization process of the amorphous Zr70Cu20Ni10 alloy is strongly influenced by the addition of nickel. Addition of 10 at% Ni to the Zr70Cu30 amorphous alloy makes the crystallization process proceed from a single-stage mode to a double-stage mode. The activation energy for crystallization of the amorphous Zr70Cu20Ni10 alloy is calculated to be about 388kJ·mol-1 on the basis of the Kissinger equation. The effects of nickel on the crystallization of the amorphous Zr70Cu20Ni10 alloy are discussed in terms of the genetics of metals. 相似文献
13.
Extended X-ray absorption fine structure (EXAFS) and molecular dynamic (MD) simulation were used to study the short-range order in Zr2Ni amorphous alloy. It is found that the bond length is significantly shorter for unlike atoms but longer for like atoms in amorphous state than that in the crystalline state. Meanwhile, the coordination number of Ni atom in amorphous structure is only half of that in ideal Zr2Ni crystalline. Based on these results, we proposed that there exists Zr2Ni-like chemical short-range order in the Zr2Ni amorphous alloy. 相似文献
14.
W. K. Wang Y. J. Wang S. A. He H. Iwasaki 《Zeitschrift für Physik B Condensed Matter》1988,69(4):481-484
The A15Nb3Si with a composition closed to stoichiometric compound has been synthesized under high pressure from a starting material of Nb77Si23 amorphous alloys. High pressure annealing was carried out in Bridgman anvils apparatus. The amorphous alloy would decompose into A15Nb3Si, bcc Nb solid solution and hexagonal phase when it was annealed under a pressure lower or a temperature higher than that for forming single phase A15Nb3Si. The yielded A15Nb3Si exhibited a superconducting transition temperatureT
c
of 19.1 K, and has been indexed unambiguously with a lattice parameter ofa=0.5093 nm. Moreover, a nonlinear relationship betweenT
c
anda has been constructed from our experimental data, and aT
c
of 27 K for stoichiometric A15Nb3Si can be expected. 相似文献
15.
Effect of Ni substitution on the formability and magnetic properties of Gd_(50)Co_(50) amorphous alloy 下载免费PDF全文
《中国物理 B》2020,(5)
A small amount of Ni was added into the binary Gd_(50)Co_(50) amorphous alloy to replace Gd in order to obtain ternary Co_(50)Gd_(50-x)Ni_x(x = 1, 2, and 3) amorphous alloys. Compared to the binary Gd_(50)Co_(50) amorphous alloy, the Co_(50)Gd_(50-x)Ni_x amorphous alloys show an enhanced Curie temperature(T_C) with a weakened formability. The maximum magnetic entropy change(-?S_m~(peak)) of the Co_(50)Gd_(50-x)Ni_x amorphous alloys is found to decrease with the increasing T_C.The adiabatic temperature rise(?T_(ad)) of the Co_(50)Gd_(47)Ni_3 amorphous alloy is superior to that of the Fe-based metallic glasses at room temperature. The variation of the T_C and -?S_~(peak) of the Gd_(50)Co_(50) amorphous alloy with Ni addition, and the mechanism involved, were discussed. 相似文献
16.
应用同步辐射小角x射线散射和差示扫描量热分析对块体非晶合金Zr5555Cu 3030Al1010Ni55结构弛豫进行了研究.实验结果表 明:经340℃、不同时间退火后的非晶内 部的电子密度涨落随退火时间的延长先增大而后减小;玻璃转变温度附近焓弛豫峰的表观激 活能则随退火时间的延长先减小而后增大.结果反映了随退火时间的延长,块体非晶合金内 部类液体区不断减少及类固体区不断增加的过程.
关键词:
小角x射线散射
块体非晶合金
结构弛豫 相似文献
17.
R. M. Khusnutdinoff A. V. Mokshin I. I. Khadeev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(1):84-92
The structural properties and microscopic collective dynamics of atoms in the amorphous metallic alloy Ni33Zr67 are studied using molecular dynamics simulations with a pair-additive model potential. The calculated equilibrium structural and dynamic characteristics are compared with experimental data on neutron diffraction and inelastic X-ray scattering. Theoretical analysis of the structural relaxation of microscopic density fluctuations for amorphous metallic alloys is performed within the Lee’s recurrent relation approach. The results of theoretical calculations for the intensity of scattering I(k, ω) for the amorphous metallic alloy Ni33Zr67 are in good agreement with the results of computer simulation and experimental inelastic X-ray scattering data. The low-frequency excitations observed in the longitudinal current spectra are related to the vibrational motions of individual atom clusters, which include Ni and Zr atoms. 相似文献
18.
Jinku Yu Qi Qiao Dongying Niu Qihua Jia Dongdong Wang Runhai Liu 《Phase Transitions》2013,86(9):761-767
The effect of plastic deformation on the crystallization kinetics of the ternary Ni–Cu–P amorphous alloy coatings prepared by electroless plating was investigated using differential scanning calorimetry. It was shown that the effective crystallization activation energy of the amorphous coatings is pronouncedly affected by the plastic deformation, indicating a decreasing tendency with deformation, the effective activation energy decreases from 199.02 to 163.71?kJ?mol?1 as the plastic deformation from 0% to 40%. And, accordingly, this leads to the decrease of crystallization temperature. Analyses were presented to discuss the possible mechanism for the notable effects of plastic deformation on the crystallization kinetics of the amorphous coatings. 相似文献
19.
Titanium oxide ceramic coatings were prepared by micro-arc oxidation (MAO) in galvanostatic regime on biomedical NiTi alloy in H3PO4 electrolyte using DC power supply. The surface of the coating exhibited a typical MAO porous and rough structure. The XPS analysis indicated that the coatings were mainly consisted of O, Ti, P, and a little amount of Ni, and the concentration of Ni was greatly reduced compared to that of the NiTi substrate. The TF-XRD analysis revealed that MAO coating was composed of amorphous titanium oxide. The coatings were tightly adhesive to the substrates with the bonding strength more than 45 MPa, which was suitable for medical applications. The curves of potentiodynamic porlarization indicated that the corrosion resistance of NiTi alloy was significantly improved due to titanium oxide formation on NiTi alloy by MAO. 相似文献
20.
The local atomic structure of Cu–Ni–Si alloy after severe plastic deformation (SPD) processing and the decomposition of supersaturated solid solution upon annealing were investigated by means of X-ray absorption spectroscopy. The coordination number and interatomic distances were obtained by analyzing experimental extend X-ray absorption fine structure data collected at the Ni K-edge. Results indicate that the environment of Ni atoms in Cu–Ni–Si alloy is strongly influenced by the deformation process. Moreover, ageing at 973 K affects strongly the atomic structure around the Ni atoms in Cu–Ni–Si deformed by equal channel angular pressing and high pressure torsion. This influence is discussed in terms of changes and decomposition features of the Cu–Ni–Si solid solution. 相似文献