Investigations of compressive strength on Cu-Hf-Al bulk metallic glasses: Compositional dependence of malleability and Weibull statistics

The study is focusing on how physical factors correlate with malleability for bulk metallic glasses (BMGs). Although great efforts have been done in these aspects, many problems still remain interesting. In this work, we investigated systematically the compositional dependence of the compressive malleability for three selected BMG samples of Cu52Hf39Al9 (C1), Cu49Hf42Al9 (C2) and Cu45Hf46Al9 (C3) in the high glass-forming Cu-Hf-Al system. Our results demonstrated that (i) with increasing of Hf content the malleability of BMGs becomes stronger, (ii) shear stress has an important impact in controlling the compressive deformation behaviors and (iii) the malleability increases linearly as the glass transition temperature and shear modulus decrease but it does not directly correlate with Poisson’s ratio and glass forming ability. Finally, through two-parameter Weibull statistics we further suggest that the C3 BMG indeed exhibits a more uniform distribution on the failing strength in a more reliable manner with respect to the other C1 and C2 cases.