Fillability and Imprintability of High-strength Ni-based Bulk Metallic Glass Prepared by the Precision Die-casting Technique

Abstract

The fillability and imprintability of a Ni-based bulk metallic glass (BMG) prepared by the precision die-casting was investigated. A threedimensional microgear made of Ni-based BMG is successfully prepared by the precision die-casting technique. The cast Ni-based BMG has excellent fillability against a microindentation formed by Vickers indentation, and the filling area obtained using a confocal scanning microscope reaches 99%. In addition, the cast Ni-based BMG exhibits excellent imprintability of the die surface even on a nanometer scale. It is therefore concluded that the Ni-based BMG is suitable as a material for micromachines due to its superior fillability and imprintability.

Developments and Applications of Bulk Glassy Alloys in Late Transition Metal Base System

“…17. 43) The constructing parts of the 1.5 mm diameter geared motor cannot be made by any mechanical machining techniques, though the 2.4 mm diameter geared motor can be scarcely constructed by mechanically machined SK-4 steel parts. It is noticed that the durability of Ni-based glassy alloy gears in the 2.4 mm diameter geared motor increased by 313 times as compared with the SK-4 steel gears.…”

Importance of surface oxide for the tribology of a Zr-based metallic glass

“…Meanwhile, metallic glasses have been recognized as potential materials for micro-electromechanical applications, such as micro-gears and media-storage devices [12,13]. This potential owes to their excellent thermoplastic formability down to the nm-scale within their undercooled liquid region [14].…”

A thermoplastic forming map of a Zr-based bulk metallic glass

“…The formability has been proposed to be the key property that determines the suitability of BMGs for TPF [37][38][39][40][41][42]. For metallic glasses of different alloy systems, the smallest replicated features [5,31,43], the maximum plastic strain that related to the large Poisson ratio and low glass transition [41] and other parameters, such as fragility and thermal stability [37,38,[44][45][46][47], have been discovered to be associated with BMGs' formability. However, for a metallic glass with a certain composition, the temperature-dependent viscosity and long processing time [5,28,42] are regarded as the two parameters that can most significantly affect the formability of BMGs.…”