Role of effective strain on the deformability of brittle Hf-based bulk metallic glass

Journal of Materials Research and Technology

Min-Ha Lee¹  Song-Yi Kim²  Eun-Soo Park³  Jürgen Eckert⁴ 

[1]Department of Materials Science, Chair of Materials Physics, Montanuniversität Leoben, Jahnstraße 12, A-8700, Leoben, Austria

[2]Advanced Process and Materials R&D Group, Korea Institute of Industrial Technology, Incheon, 21999, South Korea

[3]EML Co. Ltd., Suwon, 16229, South Korea

[4]Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700, Leoben, Austria

关键词: Bulk metallic glass;    Amorphous alloys;    Mechanical property;    Cold rolling;    Effective strain;   

DOI  :  

来源: DOAJ

【 摘 要 】

Numerical finite element method (FEM) calculation results reveal that the effective strain differs between the ductile Zr-based bulk metallic glass and brittle Hf-based bulk metallic glass (BMG) during rolling at room temperature. The current results demonstrated that the deformation mechanism of ductile Zr-based bulk metallic glass can be explained by perceptibility of multiple shear bands formation, however, the deformation mechanism of brittle Hf-based bulk metallic glass is represented by uniformly distribution of effective strain through overall specimen rather than localized into shear band. The variation of stress and the distribution of effective strain change significantly near the surface region of a Hf-based bulk metallic glass plate with increasing number of rolling passes. Under elasto-plastic deformation by cold rolling, the brittle Hf-based BMG has a thickness strain (εt) of −0.012, and the neutral effective strain (εeff) is 0.011 at the thickness direction, respectively. We present experimental confirmation that when the applied effective strain can be adjusted to below 1.1% during elasto-plastic deformation then even the brittle as-cast Hf-based BMG can be deformed up to 44% thickness reduction and 23% width expansion after multi-pass cold rolling without fracture by localization of shear stress.

【 授权许可】

Unknown