24小时热门版块排行榜    

查看: 54  |  回复: 0

yexuqing

木虫之王 (文学泰斗)

太阳系系主任

[交流] 工程化调控二维缺陷相以强化结构合金

Engineering ordered two-dimensional defect phases to strengthen structural alloys

工程化调控二维缺陷相以强化结构合金

▲ 作者:Andreas Bezold, Manuel K?brich et al.

▲链接:

https://www.science.org/doi/10.1126/science.aeh1409

▲摘要:

晶体中的缺陷通常被视为变形的结果,但也可以被设计为强化特征。平面缺陷可以强化结构合金,但通常仅在变形或服役过程中形成,限制了对某密度、稳定性和化学组成的控制。

研究者表明,预变形后时效可以将此类缺陷转化为有序缺陷相的设计架构。在单晶钴镍基高温合金和多晶钴铬钨合金中,该处理创建了致密的共格、原子级薄、有序缺陷限域相网络。这些网络将室温强度提高超过200兆帕,并将高温合金的最小蠕变速率降低三倍以上。

电子显微镜和模拟表明,局部化学有序放大了强化效果,且有序缺陷相在阻碍滑移传递的同时仍可被剪切。

▲ Abstract:

Defects in crystals are usually considered to be consequences of deformation, but they can also be engineered as strengthening features. Planar defects can strengthen structural alloys but usually form only during deformation or service, limiting control over their density, stability, and chemistry. We show that predeformation followed by aging can convert such defects into a designed architecture of ordered defect phases. In a single-crystal cobalt-nickel–based superalloy and a polycrystalline cobalt-chromium-tungsten alloy, this treatment creates dense networks of coherent, atomically thin, ordered defect–confined phases. These increase room-temperature strength by more than 200 megapascals and reduce the superalloy’s minimum creep rate by more than threefold. Electron microscopy and simulations show that local chemical ordering amplifies strengthening and that the ordered defect phases remain shearable while impeding slip transmission.
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 yexuqing 的主题更新
普通表情 龙 兔 虎 猫 高级回复 (可上传附件)
信息提示
请填处理意见