Effect of heat treatment on the structure, properties and fracture of Nd:YAG laser welded Ti-14. 8 wt% Al-21. 3 wt% Nb

Journal Article · Mon May 01 00:00:00 EDT 1989 · Scripta Metallurgica; (USA)

DOI:https://doi.org/10.1016/0036-9748(89)90518-8· OSTI ID:6906690

Baeslack, III, W A ^[1]; Cieslak, M J ^[2]

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1. Dept. of Welding Engineering, The Ohio State Univ., Columbus, OH (US)
2. Sandia National Labs., Albuquerque, NM (US)

A recent investigation by the authors showed that pulsed Nd:YAG laser welding can produce defect-free, comparatively ductile weldments in a Ti-14.8 wt% Al-21.3 wt% Nb titanium aluminide. The achievement of a bend ductility across the weldment equivalent to that of the {alpha}/{beta} processed base material was attributed to the effect of high laser weld cooling rates in suppressing {beta} decomposition to a brittle {alpha}{sub 2} microstructure and instead promoting the formation of an ordered {beta} superlattice (B2,CsCl type). Proposed aerospace applications of {alpha}{sub 2} titanium aluminides will require excursions to elevated temperatures approaching 600{degrees}C. Exposure to such thermal conditions even for relatively short durations would be expected to promote decomposition of the metastable weld fusion and heat-affected zone (HAZ) microstructures, thereby altering their mechanical properties. The purpose of the study presented in this paper was to investigate the influence of postweld heat treatment at 565{degrees}C on {beta} decomposition in the Nd:YAG laser weld fusion zone and the resulting microstructure, mechanical properties and fracture characteristics.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6906690
• Journal Information: Scripta Metallurgica; (USA), Journal Name: Scripta Metallurgica; (USA) Vol. 23:5; ISSN 0036-9748; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
360104 -- Metals & Alloys-- Physical Properties
656002 -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ALUMINIUM ALLOYS
CRYSTAL STRUCTURE
DUCTILITY
FABRICATION
FRACTURE PROPERTIES
HEAT TREATMENTS
JOINING
LASER WELDING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM ALLOYS
TEMPERATURE EFFECTS
TENSILE PROPERTIES
TITANIUM ALLOYS
WELDING