Stress-Induced Virtual Melting as a New Mechanism of Solid-Solid Phase Transformations and Stress Relaxation

应力诱导虚拟熔化作为固-固相变和应力松弛的新机制

• 批准号: 0555909
• 负责人: Valery Levitas
• 金额: --
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-15 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0555909&HistoricalAwards=false
• 关键词: Stress; Induced; Virtual; Melting; New

We recently predicted a new phenomenon, namely that crystal-crystal and crystal-amorphous phase transformations can occur via virtual melting in the nanoscale layer along the interface at temperatures significantly (more than 1000K!) below the thermodynamic melting temperature. The energy of the internal elastic stresses, induced by large transformation strain for solid-solid transformation, increases the driving force for melting and reduces the melting temperature. Melting releases the stresses and the unstable melt immediately solidifies into the stable crystalline (above the glass transition temperature) or amorphous (below the glass transition temperature) phase. Thus, virtual melting represents a new mechanism of solid-solid transformations, stress relaxation and loss of coherency at a moving solid-solid interface. The goal of this project is to develop theoretical, computational, and experimental approaches that will allow us to prove the existence, to study main features and explore the generality and applied significance of the phenomena of solid-solid transformations via virtual melting.

我们最近预测了一种新现象，即在显着低于热力学熔化温度（超过 1000K！）的温度下，可以通过沿着界面的纳米级层中的虚拟熔化来发生晶体-晶体和晶体-非晶相变。固-固转变过程中大的转变应变引起的内弹性应力的能量增加了熔化的驱动力并降低了熔化温度。熔化释放应力，不稳定的熔体立即凝固成稳定的结晶相（高于玻璃化转变温度）或非晶相（低于玻璃化转变温度）。因此，虚拟熔化代表了一种新的固-固转变、应力松弛和移动固-固界面相干性丧失的机制。该项目的目标是开发理论、计算和实验方法，使我们能够证明虚拟熔化的存在性、研究主要特征并探索固-固转变现象的普遍性和应用意义。