An improved method to estimate Young's modulus of Zr-based BMGs accounting for pile-up during nanoindentation

• We propose an improved method to estimate Young's modulus in nanoindentation.
• We extract the topography of pile-up and prove it to be elliptical.
• The variation of the contact boundary is modeled to estimate the contact area.

Considerable attention has been focused on metallic glasses for their excellent mechanical properties where nanoindentation has been widely used to estimate the material parameters, while traditional analysis of nanoindentation data can overestimate the Young's modulus and hardness due to pile-up which occurs commonly in metallic glasses. In this paper, we demonstrate an improved method to estimate the Young's modulus and hardness of Zr-based bulk metallic glasses accounting for pile-up during nanoindentation. The contact boundary of the pile-up on Zr55Cu30Al10Ni5 is investigated, a model to estimate the contact area is developed, and then we achieve the Young's modulus together with hardness directly from load–depth data. Two other Zr-based bulk metallic glasses are used for verification, and four methods including two direct methods and two scanning probe microscopy-based methods are also performed for comparison. The results of the improved method agree with the referenced Young's modulus better than those methods, proving the feasibilities and potential of the method in engineering.