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Title: The microstructure and mechanical behaviors of the Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy produced by laser melting deposition

The microstructure and mechanical properties of the Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy produced by laser melting deposition have been investigated. The columnar grains of the Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy due to the layer-by-layer epitaxial growth from the underlying template grains during laser melting deposition, which is roughly parallel to the deposition direction, had been found by optical microscopy; strong [101{sup ¯}2]{sub α} crystallographic texture has been confirmed by X-ray diffraction and electron backscattered diffraction. Depending on the last heating history, the microstructure of the alloy undergoes a continued change opposite to the deposition direction: martensitic α′ (transformed β); coarsened primary α laths with transformed β; coarsened primary α laths; and the fine basketweave microstructure with a few coarsened α laths or annealed martensitic α′. The average Vickers micro-hardness value of the alloy is 364 HV. The alloy parallel to the deposition direction presents lower tensile strength (925 MPa) and better elongation (18.8%), compared with 1025 MPa and 8.2% of that vertical to the deposition direction, which has been discussed using its microstructure characterization. - Highlights: • The columnar grains and strong [101{sup ¯}2]{sub α} crystallographic texture of the Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy due to the epitaxial growth from the underlying template grains • The microstructure evolution ofmore » the alloy depends on the last heating history. • The specimen parallel to the deposition direction presents lower ultimate tensile strength and higher elongation than the specimen vertical to the deposition direction.« less
Authors:
; ;  [1] ;  [1] ;  [2]
  1. Liaoning Key Materials Laboratory for Railway, School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, Liaoning Province (China)
  2. School of Materials Science and Engineering, Beihang University, 100191 Beijing City (China)
Publication Date:
OSTI Identifier:
22403592
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 97; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; ANNEALING; CRYSTAL STRUCTURE; DEPOSITION; ELONGATION; EPITAXY; HARDNESS; LASER RADIATION; LAYERS; MARTENSITIC STEELS; MELTING; MICROSTRUCTURE; MOLYBDENUM ALLOYS; OPTICAL MICROSCOPY; SILICON ALLOYS; TENSILE PROPERTIES; TEXTURE; TITANIUM ALLOYS; X-RAY DIFFRACTION; ZIRCONIUM ALLOYS