3D printing metals like thermoplastics: Fused filament fabrication of metallic glasses

Yet-Ming Chiang,Ling Shao,Richard Fontana,Emanuel M Sachs,Punnathat Bordeenithikasem,Christopher A Schuh,Jonah S Myerberg,Wen Chen,A John Hart,Peter Schmitt,Matthew D Verminski,Joseph Shim,Jan Schroers,Ric Fulop,Jittisa Ketkaew,Andrew Roberts,Nicholas M Mykulowycz,Michael A Gibson

doi:10.1016/j.mattod.2018.07.001

Abstract

Abstract Whereas 3D printing of thermoplastics is highly advanced and can readily create complex geometries, 3D printing of metals is still challenging and limited. The origin of this asymmetry in technological maturity is the continuous softening of thermoplastics with temperature into a readily formable state, which is absent in conventional metals. Unlike conventional metals, bulk metallic glasses (BMGs) demonstrate a supercooled liquid region and continuous softening upon heating, analogous to thermoplastics. Here we demonstrate that, in extension of this analogy, BMGs are also amenable to extrusion-based 3D printing through fused filament fabrication (FFF). When utilizing the BMGs’ supercooled liquid behavior, 3D printing can be realized under similar conditions to those in thermoplastics. Fully dense and amorphous BMG parts are 3D printed in ambient environmental conditions resulting in high-strength metal parts. Due to the similarity between FFF of thermoplastics and BMGs, this method may leverage the technology infrastructure built by the thermoplastic FFF community to rapidly realize and proliferate accessible and practical printing of metals.

Highlights

The materials toolbox has traditionally demanded hard choices [1]
Zr44Ti11Cu10Ni10Be25 was selected as a model system to study metallic glass material extrusion because it is widely characterized, commercially available, and has high thermoplastic formability [28,29,30]
Amorphous Zr44Ti11Cu10Ni10Be25 rods with 1 mm diameter and up to 70 cm length were used as printing media

Summary

Introduction

While the structural performance of metals is superior to that of thermoplastics, processing of metals is generally challenging (Fig. 1). Plastics, thermoplastics, can be readily processed into complex geometries, but exhibit inferior structural performance [1]. A contemporary example is additive manufacturing (AM), which, for thermoplastics, has enabled 3D printing of complex shapes through a material extrusion process, called fused filament fabrication (FFF). The versatility and practicality for AM of metals lags significantly behind [2]. This is essentially due to the inability to maintain metals at viscosities on practical time scales that would be suited for processing/forming operations such as material extrusion in FFF processes (Fig. 1)

Methods

Results

Discussion

Conclusion