关于变形诱导非平衡固溶的再思考

来源期刊：上海金属2011年第3期

论文作者：林一坚

文章页码：55 - 62

关键词：强塑性变形； 非平衡固溶； 珠光体钢； 渗碳体溶解； 化学位

Key words：Severe Plastic Deformation； Non-Equilibrium Solid Solution； Pearlitic Steel； Cementite Dissolution； Chemical Potential

摘    要：对珠光体钢在变形中发生渗碳体溶解的研究工作作了系统的综述,在归纳和总结大量实验事实的基础上指出,合金的变形态作为热力学非平衡状态,不能沿用平衡相图的数据;而在其局部结构上,在原子活动范围内仍遵循化学位平衡的原则。变形在基体中引入大量可与溶质原子交互作用的缺陷,同时又破坏第二相中的结合键使其自由能提高,由此驱使溶质原子从第二相向基体低能区转移,导致第二相溶解。同样的原理也适用于其它的变形合金。

Abstract: Investigations on cementite dissolution of pearlitic steel during deformation were summarized.Based on a lot of experimental facts,it is pointed out that,while data of phase diagram cannot be applied to a deformed alloy as it is not in thermodynamic equilibrium state,the principle of chemical potential equilibrium is still followed within its local microstructure where correlative atoms are mobile enough to move about.Deformation causes a variety of defects in the matrix which interact with solute atoms and,meanwhile,destroys chemical bonds of the second phase,which increases its free energy.As a result,solute atoms are driven from the second phase into the matrix,leading to dissolution of the second phase.This mechanism also works in other deformed alloys.