INFLUENCE OF PHOSPHORUS IN DILUTE SOLID SOLUTION ON ABSOLUTE SURFACE AND GRAIN BOUNDARY ENERGIES OF IRON
INFLUENCE OF PHOSPHORUS IN DILUTE SOLID SOLUTION ON ABSOLUTE SURFACE AND GRAIN BOUNDARY ENERGIES OF IRON
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DOI：
10.1098/rspa.1965.0158
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发表时间：
1965-01-01
影响因子：
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通讯作者：
HONDROS, ED
中科院分区：
文献类型：
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作者：
HONDROS, ED
一种测定铁和铁合金在熔点以下温度下的绝对表面能的技术已经发展起来。该技术是基于测量薄箔的收缩力。所有的测量都在现场进行，整个实验过程中保持化学平衡。结果表明：1450℃时，稀固溶体中的磷使铁的表面能从2100 ergs cm-2逐渐降低到1200 ergs cm-2，使铁的磷含量增加0.36%；结果也得到了γ相，其中效果不太明显。绝对晶界能也被确定为磷含量的函数。从箔片的应变速率出发，推导出其自扩散系数随磷含量的增加而线性增加。应用吉布斯吸附定理，可以对溶质与界面的平衡偏析程度进行评价。最大能级为2.3 x 10-9g原子cm-2at表面和1.1 x 10-9g原子cm-2at晶界。讨论了这些测量结果与铁/磷合金晶间脆性断裂问题的相关性。
A technique has been developed for the determination of the absolute surface energies of iron and iron alloys at temperatures of up to the melting point. The technique is based upon the measurement of the contractile forces in thin foils. All measurements are madein situand chemical equilibrium is maintained throughout the experiment. The results show that phosphorus in dilute solid solution decreases progressively the surface energy of iron at 1450 °C from 2100 ergs cm-2to 1200 ergs cm-2, for increasing phosphorus contents of up to 0.36%. Results were also obtained for the γ phase in which the effect is less pronounced. Absolute grain boundary energies were also determined as a function of phosphorus content. From the strain rate of the foils which move by a diffusion creep mechanism, it was deduced that the self diffusion coefficient increases linearly with phosphorus content. Application of the Gibbs adsorption theorem has permitted the evaluation of the extents of equilibrium segregation of the solute to interfaces. The maximum levels are 2.3 x 10-9g-atom cm-2at surfaces and 1.1 x 10-9g-atom cm-2at grain boundaries. The relevance of these measurements to the problem of the intergranular brittle fracture of iron/phosphorus alloys is discussed.