PT  - JOURNAL ARTICLE
AU  - Cao, Chezheng
AU  - Yao, Gongcheng
AU  - Jiang, Lin
AU  - Sokoluk, Maximilian
AU  - Wang, Xin
AU  - Ciston, Jim
AU  - Javadi, Abdolreza
AU  - Guan, Zeyi
AU  - De Rosa, Igor
AU  - Xie, Weiguo
AU  - Lavernia, Enrique J.
AU  - Schoenung, Julie M.
AU  - Li, Xiaochun
TI  - Bulk ultrafine grained/nanocrystalline metals via slow cooling
AID  - 10.1126/sciadv.aaw2398
DP  - 2019 Aug 01
TA  - Science Advances
PG  - eaaw2398
VI  - 5
IP  - 8
4099  - http://advances.sciencemag.org/content/5/8/eaaw2398.short
4100  - http://advances.sciencemag.org/content/5/8/eaaw2398.full
SO  - Sci Adv2019 Aug 01; 5
AB  - Cooling, nucleation, and phase growth are ubiquitous processes in nature. Effective control of nucleation and phase growth is of significance to yield refined microstructures with enhanced performance for materials. Recent studies reveal that ultrafine grained (UFG)/nanocrystalline metals exhibit extraordinary properties. However, conventional microstructure refinement methods, such as fast cooling and inoculation, have reached certain fundamental limits. It has been considered impossible to fabricate bulk UFG/nanocrystalline metals via slow cooling. Here, we report a new discovery that nanoparticles can refine metal grains to ultrafine/nanoscale by instilling a continuous nucleation and growth control mechanism during slow cooling. The bulk UFG/nanocrystalline metal with nanoparticles also reveals an unprecedented thermal stability. This method overcomes the grain refinement limits and may be extended to any other processes that involve cooling, nucleation, and phase growth for widespread applications.