Fabrication of Functionally Graded Ti and γ-TiAl by Laser Metal Deposition

Abstract

TiAl alloys have become a popular choice in the aerospace and automotive industries, owing to their high specific yield strength, specific modulus, and oxidation resistance over titanium alloys and Ni-based super alloys at elevated temperatures. Although laser metal deposition (LMD) techniques have been available for manufacturing metal alloys for a decade, limited research has been focused on joining intermetallic materials with dissimilar materials using LMD. Here, LMD was used to join titanium aluminide Ti-48Al-2Cr-2Nb and commercially pure titanium with an innovative transition path. The theorized transition was implemented by fabricating functionally graded material (FGM). Porosity- and crack-free deposits were successfully fabricated. Energy dispersive x-ray spectroscopy analysis revealed the final composition was very close to the design composition. X-ray diffraction showed the expected phases were formed. The Vickers hardness, ultimate tensile strength, and coefficient of thermal expansion were evaluated to characterize the FGM's mechanical and physical properties. The properties of the material were comparable to those of as-cast material as reported in the literature.

Department(s)

Materials Science and Engineering

Second Department

Mechanical and Aerospace Engineering

Keywords and Phrases

Aluminum Alloys; Automotive Industry; Beams and Girders; Binary Alloys; Chromium Alloys; Deposition; Dissimilar Materials; Energy Dispersive Spectroscopy; Functionally Graded Materials; Industrial Research; Intermetallics; Nickel Alloys; Niobium Alloys; Tensile Strength; Thermal Expansion; Titanium; Titanium Compounds; Vickers Hardness; X ray Diffraction; X ray Spectroscopy; Aerospace and Automotive Industries; Commercially Pure Titaniums; Energy Dispersive X-Ray Spectroscopy Analysis; Functionally Graded Material (FGM); Intermetallic Materials; Laser Metal Deposition; Mechanical and Physical Properties; Ultimate Tensile Strength; Titanium Alloys

International Standard Serial Number (ISSN)

1047-4838; 1543-1851

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Minerals, Metals and Materials Society (TMS), All rights reserved.

Publication Date

01 Dec 2017

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