Yield strength and yield strain of metallic glasses and their correlations with glass transition temperature

• Published in: Journal of alloys and compounds 2015-07, Vol.637, p.44-54
• Main Authors: Qu, R.T., Liu, Z.Q., Wang, R.F., Zhang, Z.F.
• Format: Article
• Language: English
• Subjects: Alloy systems; Amorphous materials; Constants; Glass transition temperature; Metallic glass; Metallic glasses; Shear transformation zone; Strain; Strength; Yield strain; Yield strength
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2015.03.005

[Display omitted] •Yield strengths, elastic modulus and glass transition temperatures of ∼300 metallic glasses are presented.•The yield strains of metallic glasses are not always constant but dependent on glass transition temperatures.•Simple relations among yield strength, yield strain and glass transition temperature are derived.•The results support that glass transition and mechanical yielding share same thermodynamic origin.•High elasticity, high strength and high thermostability can be synchronously achieved for metallic glasses. Strength should be the most outstanding mechanical property for metallic glasses (MGs). Here we analyze the strengths of MGs with more than 300 compositions in ∼30 alloy systems covering nearly all strength levels, ranging from 0.3GPa to 6GPa. With these abundant experimental data available, we find that the yield strain is not always constant but depends on glass transition temperature, Tg, ranging from 1% to 2.5% for normal strain and from 1.2% to 3.4% for shear strain. This can be well explained by assuming an equivalent energy barrier for yielding and glass transition. Relations derived based on this assumption show that MGs with high Tg may yield with larger critical strain and higher strength, implying that high elasticity, high strength and high thermostability can be synchronously achieved for MGs.