The effects of cooling rate XD trademark TiAl weld microstructures

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6838492

Robertson, E ^[1]; Hill, M A; Schwarz, R B ^[2]

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1. Air Force Office of Scientific Research, Bolling AFB, DC (USA)
2. Los Alamos National Lab., NM (USA)

Fusion zone microstructures of an electron beam (EB) welded XD{trademark} Ti-48at % Al + 6.5 vol% TiB{sub 2} alloy revealed the presence of a plate-like microstructural constituent which was absent in the base metal. The volume fraction of this phase increased with increasing cooling rate and correlated with increased weld cracking frequency. To determine whether this phase was a product of solidification from the melt or a product of a solid-state transformation, weld microstructures were compared to those cycled in a Gleebel 1500/20 Thermal-Mechanical Test System which was programmed to simulate the solid-state portion of the weld cooling rates (as predicted by a Rosenthal analysis). Both weld and simulation microstructures were characterized using X-ray diffraction, optical and scanning electron microscopy. The plate-like phase found in the weld microstructures was identified as TiB{sub 2} occurring upon rapid solidification of the melted weld metal. 11 refs., 8 figs.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOD; DOE/DP; DOE/ER
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6838492
• Report Number(s): LA-UR-90-1616; CONF-900466-46; ON: DE90011975
• Resource Relation: Conference: Spring meeting of the Materials Research Society, San Francisco, CA (USA), 16-21 Apr 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
WELDED JOINTS
TITANIUM ALLOYS
MICROSTRUCTURE
COOLING
INTERMETALLIC COMPOUNDS
TITANIUM BORIDES
X-RAY DIFFRACTION
ALLOYS
BORIDES
BORON COMPOUNDS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
JOINTS
SCATTERING
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360102* - Metals & Alloys- Structure & Phase Studies
360101 - Metals & Alloys- Preparation & Fabrication