Controlling the Mechanical Properties of Bulk Metallic Glasses by Superficial Dealloyed Layer

Abstract

Cu50Zr45Al5 bulk metallic glass (BMG) presents high fracture strength. For improving its plasticity and controlling its mechanical properties, superficial dealloying of the BMG was performed. A composite structure containing an inner rod-shaped Cu-Zr-Al amorphous core with high strength and an outer dealloyed nanoporous layer with high energy absorption capacity was obtained. The microstructures and mechanical properties of the composites were studied in detail. It was found, for the first time, that the mechanical properties of Cu50Zr45Al5 BMG can be controlled by adjusting the width of the buffer deformation zone in the dealloyed layer, which can be easily manipulated with different dealloying times. As a result, the compressive strength, compressive strain, and energy absorption capacity of the BMGs can be effectively modulated from 0.9 to 1.5 GPa, from 2.9% to 4.7%, and from 29.1 to 40.2 MJ/m3, respectively. The paper may open a door for developing important engineering materials with regulable and comprehensive performances.

Nanoporous Gold and Other Related Materials

“…The ability to form macroscopic size samples of np-Au enables their study by special nanoidentation methods, as are described in the paper. The interconnected morphology of ligaments and pores that is seen in np-Au is also found in other nanostructured metals, such as nanoporous copper (NPC) formed on the surface of the bulk metallic glasses (BMG) of the alloy Cu 50 Zr 45 A l5 by HF treatment, as studied in the paper by Wang and coworkers [20]. These rod like structures with a BMG interior and NPC shell are shown to exhibit superior energy absorption properties.…”

Electrochemical Surface Nanostructuring of Ti47Cu38Fe2.5Zr7.5Sn2Si1Ag2 Metallic Glass for Improved Pitting Corrosion Resistance

“…[ 44 ] Likewise, classical acid etching treatments in HF or HCl solutions are not applicable since they will enhance Cu at the surface, thus inducing local corrosion and diminishing the mechanical performance. [ 45,46 ]…”

“…[44] Likewise, classical acid etching treatments in HF or HCl solutions are not applicable since they will enhance Cu at the surface, thus inducing local corrosion and diminishing the mechanical performance. [45,46] For the stimulation of bone tissue forming cells, nanostructured implant surfaces with an oxidic nature are most suitable. [47] To achieve tailored nanoporous structures and a substantial reduction of Cu species in the near-surface Ti-Cu-based BMG region, techniques adapted from dealloying emerge promising.…”

Isokinetic Analysis of Fe41Co7Cr15Mo14Y2C15B6 Bulk Metallic Glass: Effect of Minor Copper Addition

“…In recent years, many attempts have been made to generate new amorphous alloys and bulk metallic glasses (BMGs) with better properties and performance [ 1 , 2 , 3 ]. These efforts have led to the design and development of advanced BMGs with special properties such as high strength and hardness [ 4 , 5 , 6 , 7 ], relatively good corrosion resistance [ 8 , 9 , 10 ] and excellent magnetic properties [ 11 , 12 , 13 ].…”