Enhanced Impact Toughness at Ambient Temperatures of Ultrafine-Grained Al-26 wt.% Si Alloy Produced by Equal-Channel Angular Pressing
Overcoming general brittleness of hypereutectic Al-Si alloys is in urgent need for expanding their application in automotive, aerospace and construction industries. A unique phenomenon was observed that bulk ultrafine-grained Al-26 wt.% Si alloy, produced by severe plastic deformation via equal-channel angular pressing, exhibited higher toughness at the impact temperature of − 196 ~ 100 °C than the coarse-grained casting alloy. The improvement in impact toughness at all testing temperatures was mainly due to the homogeneous ultrafine-grained structure with the breakage of brittle primary silicon crystals, which generated more and deeper fracture dimples that consumed much higher fracture energy. It indicates the advantage of bulk ultrafine-grained Al-Si alloys and spurs their application interest at various ambient temperatures.
Keywordsambient temperature Al-Si alloy equal-channel angular pressing (ECAP) impact toughness ultrafine-grained (UFG)
The study was supported by the Fundamental Research Funds for the Central Universities (Grant No. HHU2016B10314), Six Major Talent Peaks Project of Jiangsu Province of China (Grant Number 2014-XCL-023),the Key Research and Development Project of Jiangsu Province of China (Grant No. BE2017148), Public Service Platform Program (Grant No. M201614) and Science & Technology Support Program in the industrial field (Grant No. H201615) of Suqian City of China.