Cooling rate effects in Ti-6Al-2Sn-4Zr-2Mo weldments

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02664909· OSTI ID:5897877

Baeslack, W A; Mullins, F D

Weldment performance in near-alpha titanium alloys is dependent primarily on the structure and properties of the fusion zone. For gas tungsten-arc welds in sheet materials, the columnar beta grain morphology associated with the fusion zone does not vary appreciably with weld energy input. As a result, the control of mechanical properties in this region can only be accomplished by controlling the transformed-beta microstructure. An early study of continuous-cooling phase transformations in the near-alpha titanium alloy Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) investigated the effect of cooling rate on microstructure of simulated weld specimens. Although the fine scale of the beta decomposition products limited their effective characterization using light microscopy, the investigation did recognize the complex nature of microstructures produced at intermediate cooling rates between about 10 and 100/sup 0/C per second. A more recent transmission-electron microscopy study of a gas tungsten-arc weldment in Ti-6242 confirmed the complexities associated with both the fusion and heat-affected zone microstructures, and determined these regions to be different combinations of diffusional alpha and alpha-prime martensite. Since cooling rates experienced in the fusion zone of gas tungsten-arc welds in titanium can range from about 5 to 125/sup 0/C per second, it would be desirable to have a more complete understanding of how cooling rate influences both the weld fusion zone microstructure and mechanical properties. The purpose of this study was to develop this understanding.

• Research Organization: The Ohio State University, Columbus, OH
• OSTI ID: 5897877
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 15A:10; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360100* -- Metals & Alloys
ALLOYS
ALUMINIUM ALLOYS
ARC WELDING
COHERENT SCATTERING
COOLING
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
DIFFRACTION
DIFFUSION
FABRICATION
GAS TUNGSTEN-ARC WELDING
HEAT TREATMENTS
JOINING
JOINTS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ALLOYS
SCATTERING
SIMULATION
STRUCTURAL CHEMICAL ANALYSIS
TEMPERATURE EFFECTS
THERMAL CYCLING
TIN ALLOYS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
WELDED JOINTS
WELDING
X-RAY DIFFRACTION
ZIRCONIUM ALLOYS