Abstract

The structural factors that lead to a decrease in the mechanostability of ultrafine-grained (UFG) metals and alloys during creep tests at increased temperatures have been revealed using small-angle X-ray scattering, electron microscopy, and the measurements of the density. An important factor is found to be nanopores that form during severe plastic deformation. The development of these nanopores in grain boundaries, which form during the creep, occurs by a diffusion mechanism and leads to the fracture. The role of disperse inclusions and high-angle grain boundaries in the strength of UFG metals and alloys during their “short-time” and long-term loadings is considered.

中文翻译：

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严重塑性变形产生的超细晶粒金属和合金的蠕变测试过程中缺陷结构的演变

摘要

使用小角度X射线散射，电子显微镜和密度测量揭示了导致在高温下蠕变测试期间超细晶粒（UFG）金属和合金的机械加工性能降低的结构因素。发现一个重要因素是在严重塑性变形过程中形成的纳米孔。这些纳米孔在蠕变过程中形成的晶粒边界的发展是通过扩散机制发生的，并导致断裂。考虑了在短时间和长期载荷下，UFG金属和合金中分散夹杂物和高角度晶界在强度方面的作用。