arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1001.3549cond-mat.mtrl-scicond-mat.stat-mech
收藏

固-固相变微结构选择的时空方法

Space-time approach to microstructure selection in solid-solid transitions

Surajit Sengupta, Jayee Bhattacharya, Madan Rao

摘要:

固体中固体的成核是由明显的动力学不均匀性的出现引发的,这种不均匀性由“活性”粒子组成,其轨迹显示出从弹道到扩散的突然转变,与微观结构从{ \it孪晶马氏体}到{ \it铁素体}的不连续转变相一致。活性颗粒表现出间歇性的堵塞和流动。活性粒子轨迹的性质决定了转化固体的命运--在抑制单粒子扩散时,转化通过罕见的弦状相关激发进行,从而产生孪晶马氏体核。这些弦状的激发沿着由不活跃粒子建立的势能地形中的脊流动。我们使用轨迹空间中的热力学来描述这种转变,即活性粒子被非活性粒子限制的动力学作用。我们的研究汇集了玻璃,堵塞,塑性和固体成核的物理学。

英文摘要:

Nucleation of a solid in solid is initiated by the appearance of distinct dynamical heterogeneities, consisting of `active' particles whose trajectories show an abrupt transition from ballistic to diffusive, coincident with the discontinuous transition in microstructure from a {\it twinned martensite} to {\it ferrite}. The active particles exhibit intermittent jamming and flow. The nature of active particle trajectories decides the fate of the transforming solid -- on suppressing single particle diffusion, the transformation proceeds via rare string-like correlated excitations, giving rise to twinned martensitic nuclei. These string-like excitations flow along ridges in the potential energy topography set up by inactive particles. We characterize this transition using a thermodynamics in the space of trajectories in terms of a dynamical action for the active particles confined by the inactive particles. Our study brings together the physics of glass, jamming, plasticity and solid nucleation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑