Solute diffusion in liquid nickel measured by pulsed ion beam melting
Solute diffusion in liquid nickel measured by pulsed ion beam melting
复制标题
通过脉冲离子束熔化测量液态镍中的溶质扩散
DOI：
10.1007/s11661-004-0227-0
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
M. Aziz
中科院分区：
文献类型：
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作者：
J. Leonard;T. Renk;M. Thompson;M. Aziz
用脉冲离子束熔炼技术测定了稀钨和钼在镍液中的液相扩散系数。一束高强度的氮离子束聚焦在注入了已知W和Mo浓度分布的镍衬底表面。表面熔化到∼1微米的深度，可以在熔化时加宽植入物的轮廓。用卢瑟福背散射光谱仪测定了熔融前后的溶质浓度-深度分布。通过一系列数值模拟来估算1755-2022K范围内平均液体温度的熔体历史和扩散展宽，通过与测量的深度分布进行比较，确定了每种情况下的有效扩散系数。W为(2.4±0.2)×10−5 cm~2/S，Mo为(1.6±0.4)×10−5 cm~2/S，由于仪器效应和表面效应，系统不确定度为±0.5×10−5。
Measurements of liquid-phase diffusion coefficients for dilute tungsten and molybdenum in molten nickel were made using a pulsed ion-beam melting technique. A high-intensity beam of nitrogen ions is focused on the surface of a nickel substrate that was implanted with known concentration profiles of W and Mo. Melting of the surface to a depth of ∼1µm allows broadening of the implant profiles while molten. Solute concentration-depth profiles were determined before and after melting using Rutherford backscattering spectrometry. Using a series of numerical simulations to estimate the melt history and diffusional broadening for mean liquid temperatures in the range 1755 to 2022 K, an effective diffusion coefficient is determined in each case by comparison to the measured depth profiles. This is found to be (2.4±0.2)×10−5cm2/s for W and (1.6±0.4)×10−5cm2/s for Mo, with an additional systematic uncertainty of ±0.5×10−5due to instrumental and surface effects.