Direct Laser Deposition of Ti-6Al-4V from Elemental Powder Blends

Abstract

Purpose - This paper aims to achieve Ti-6Al-4V from Ti, Al and V elemental powder blends using direct laser deposition (DLD) and to understand the effects of laser transverse speed and laser power on the initial fabrication of deposit's microstructure and Vickers hardness.

Design/methodology/approach - Two sets of powder blends with different weight percentage ratio for three elemental powder were used during DLD process. Five experiments with different processing parameters were performed to evaluate how microstructure and Vickers hardness change with laser power and laser transverse speed. Energy dispersive X-ray spectroscopy, optical microscopy and Vickers hardness test were used to analyze deposits' properties.

Findings - This paper reveals that significant variance of elemental powder's size and density would cause lack of weight percentage of certain elements in final part and using multiple coaxial powder nozzles design would be a solution. Also, higher laser power or slower laser transverse speed tend to benefit the formation of finer microstructures and increase Vickers hardness.

Originality/value - This paper demonstrates a new method to fabricate Ti-6Al-4V and gives out a possible weight percentage ratio 87:7:6 for Ti:Al:V at powder blends during DLD process. The relationship between microstructure and Vickers hardness with laser power and laser transverse speed would provide valuable reference for people working on tailoring material properties using elemental powder method.

Department(s)

Materials Science and Engineering

Second Department

Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

This work was conducted as part of NASA’s project through EPSCoR Grant #NNX13AM99A. The support from Boeing is also gratefully acknowledged.

Keywords and Phrases

Microstructure; Ti-6Al-4V; Composition distribution; DLD process; Elemental powder; Vickers hardness

International Standard Serial Number (ISSN)

1355-2546

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 Emerald, All rights reserved.

Publication Date

15 Aug 2016

Link to Full Text

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