Ostwald ripening in ternary alloys
Ostwald ripening in ternary alloys
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DOI：
10.1007/bf02649761
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发表时间：
1996-04-01
影响因子：
2.8
通讯作者：
Voorhees, PW
中科院分区：
文献类型：
--
作者：
Kuehmann, CJ;Voorhees, PW
一种理论的粗化在等温，三元合金在努力了解第三种化学成分对成熟行为的两相系统的影响发展。该分析适用于一般的、非理想的、非稀释的溶液，但仅限于粗化相的极小体积分数，并且忽略了扩散矩阵中的非对角线项。经过粗化的三元体系中的Gibbs-Thompson方程揭示了颗粒/基体界面上的浓度不仅依赖于颗粒半径，还依赖于远场过饱和度。此外，毛细管长度取决于两组分的扩散系数。渐近分析表明，平均粒子半径、单位体积粒子数和矩阵过饱和度的时间幂律指数与二元极限下的指数相同；然而，幂律的振幅被修改了。我们发现，基体过饱和的轨迹必须沿着一条领带，但颗粒组成的轨迹不是。给出了稀三元加入物对二元合金粗化率影响的表达式。
A theory of coarsening in an isothermal, ternary alloy is developed in an effort to understand the effects of a third chemical component on the ripening behavior of a two-phase system. The analysis is valid for a general, nonideal, nondilute solution, but is limited to extremely small volume fractions of the coarsening phase and neglects off-diagonal terms in the diffusion matrix. The Gibbs-Thompson equation in a ternary system undergoing coarsening reveals that the concentrations at the particle/matrix interface are dependent on the far-field supersaturations as well as on the particle radius. In addition, the capillary length depends on the diffusivities of the two components. An asymptotic analysis shows that the exponents of the temporal power laws for the average particle radius, number of particles per unit volume, and the matrix supersaturations are the same as that found in the binary limit; however, the amplitudes of the power laws are modified. We find that the trajectory of the matrix supersaturation must lie along a tie-line, but the trajectory of the particle composition does not. An expression for the effect of dilute ternary additions to the coarsening rate of a binary alloy is also given.