Impact of micro-alloying on the plasticity of Pd-based Bulk Metallic Glasses

TL;DR

This study investigates how micro-alloying Pd-based bulk metallic glasses with Co and Fe affects their plasticity, revealing that minor alloying elements can significantly alter deformation behavior without changing elastic properties.

Contribution

It provides new insights into the effects of micro-alloying on the plasticity of Pd-based bulk metallic glasses, highlighting the role of minor elements in deformation behavior.

Findings

Co addition increased plastic strain to 13%

Fe addition caused immediate failure after elastic limit

Poisson's ratio remained unchanged despite alloying

Abstract

Micro-alloying was performed using additions of Co and Fe to monolithic Pd40Ni40P20 bulk metallic glass to study selectively the influence on the plastic behavior in uniaxial compression and three-point bending tests. The corresponding Poisson's ratios were determined by ultrasonic measurements. The microstructure of the individual bulk metallic glasses was characterized by electron microscopy, X-ray diffraction and calorimetry. A plastic strain of 13% was found for the Co addition (1 at.%), whereas the Fe addition (0.6 at.%) led to immediate failure after reaching the elastic limit. Surprisingly, the plasticity is not reflected by the high Poisson's ratio of 0.4 since it remained unaffected by the minor alloying.