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.