Surface Modification of the EBM Ti-6Al-4V Alloy by Pulsed Ion Beam

Natalia Pushilina,Ekaterina Stepanova,Andrey Stepanov,Maxim Syrtanov

doi:10.3390/met11030512

Abstract

The effect of surface modification of Ti-6Al-4V samples manufactured by electron beam melting (EBM) using a pulsed carbon ion beam is studied in the present work. Based on the results of XRD, SEM, and TEM analysis, patterns of changes in the microstructure and phase composition of the EBM Ti-6Al-4V alloy, depending on the number of pulses of pulsed ion beam exposure, are revealed. It was found that gradient microstructure is formed as a result of pulsed ion beam irradiation of the EBM Ti-6Al-4V samples. The microstructure of the surface layer up to 300 nm thick is represented by the (α + α”) phase. At depths of 0.3 μm, the microstructure is mixed and contains alpha-phase plates and needle-shaped martensite. The mechanical properties were investigated using methods of uniaxial tensile tests, micro- and nanohardness measurements, and tribological tests. It was shown that surface modification by a pulsed ion beam at an energy density of 1.92 J/cm2 and five pulses leads to an increase in the micro- and nanohardness of the surface layers, a decrease in the wear rate, and a slight rise in the plasticity of EBM Ti-6Al-4V alloy.

Highlights

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According to the results of the scanning electron microscopy, the structure of the manufactured samples is characterized by the presence of relatively large initial β-grains, the internal volume of which is represented by α-plates combined in colonies (Figure 1a)
It has been demonstrated that modification of the electron beam melting (EBM) Ti-6Al-4V alloy with a pulsed beam of carbon ions causes significant changes in thin surface layers of the material; depending on the processing mode, it can improve the mechanical properties of the alloy

Summary

Introduction

Additive technologies (AT) have been actively introduced into the production of products from titanium and its alloys [4,5,6,7,8,9,10]. The advantages of AT over traditional methods for the production of metallic products are undeniable; high speed of production and the ability to obtain products of a unique geometric shape should be noted as the most significant [4]. The use of AT makes it possible to create materials of a new generation with a unique set of properties [4,5,6,7,8,9,10,11]. Optimization of the properties of additively manufactured materials can be achieved by several methods. One such method may be the selection of the optimal mode of sample production

Objectives

Methods

Results

Discussion

Conclusion