Synthesis of Ti–Al Bimodal Powder for High Flowability Feedstock by Electrical Explosion of Wires

Marat Lerner,Nikita Toropkov,Olga Bakina,Alexander Pervikov,Elena Glazkova,Konstantin Suliz,Nikolay Rodkevich,Sergey Kazantsev

doi:10.3390/met12030478

Abstract

In this research, Ti–Al bimodal powders were produced by simultaneous electrical explosion of titanium and aluminum wires. The resulting powders were used to prepare powder–polymer feedstocks. Material characterization involving X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and melt flow index (MFI) determination were carried out to characterize bimodal powders obtained and evaluate the influence of the powder composition on the feedstock flowability. The bimodal distribution of particles in powders has been found to be achieved at a current density of 1.2 × 107 A/cm2 (the rate of energy input is 56.5 J/μs). An increase in the current density to 1.6 × 107 A/cm2 leads to a decrease in the content of micron particles and turning into a monomodal particle size distribution. The use of bimodal powders for powder–polymer feedstocks allows to achieve higher MFI values compared with monomodal powders. In addition, the use of electroexplosive synthesis of bimodal powders makes it possible to achieve a homogeneous distribution of micro- and nanoparticles in the feedstock.

Highlights

Additive manufacturing (AM) technology for fabrication of complex shaped parts has many important applications in the automobile, aerospace and energy industries, biomedical applications and in other fields [1,2]
Ti–Al particles were obtained by the electrical explosion of wires (EEW) of the titanium and aluminum wires in an argon medium
The energy input time falls from 2.6 μs to 2 μs, which contributes to a decrease in the width of the particle size distribution in powders obtained by EEW method [26]

Summary

Introduction

Additive manufacturing (AM) technology for fabrication of complex shaped parts has many important applications in the automobile, aerospace and energy industries, biomedical applications and in other fields [1,2]. Fabrication of the parts by extrusion of thermoplastic polymer materials (FDM method) is a widespread method [3,4]. The possibility of AM of 3D objects using feedstocks considered as composite material comprising metal or ceramic micropowders and a polymer binder has been shown [5]. To reduce the viscosity of the feedstock, the use of binders such as wax or polyethylene glycol (PEG) was proposed [6,7]. To improve the performance of the parts fabricated, the promising solution is to incorporate nanoparticles into the feedstock formulation. The nanoparticles in the feedstock formulation are considered as an additional binder used in combination with a polymer binder. It was noted that the hardness of the sintered material increases as the fraction of nanoparticles in the feedstock increases [8]

Methods

Results

Conclusion