Alfonso Ngan

Abstract:

It is well-known that micron-sized metallic single-crystals exhibit a smaller-being-stronger size effect. For single crystals, the yield strength in general varies with specimen size approximately as a power law. For specimens containing microstructures, however, how the internal microstructure length scale, such as grain size and precipitate spacing, affects the strength of small metal volumes is an open area. In this work, the relevant experimental and theoretical efforts are reviewed. The results reveal intricate coupling effects between the external specimen size and the internal microstructural length scales. Essentially, the strength and plasticity of small metal volumes containing real microstructures can significantly deviate from their bulk counterparts, as well as from monolithic single crystals.