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Title: Novel concepts in weld metal science: Role of gradients and composite structure

Technical Report ·
DOI:https://doi.org/10.2172/6069967· OSTI ID:6069967

The effects of compositional and microstructural gradients on weld metal properties are being investigated. Crack propagation is solidified alloy structures is being characterized as to solidification orientation and the profile of the compositional variations. The effects of compositional gradients, are considered based on a thermodynamic analysis, referred to as the Cahn-Hillard analysis, which describes the degree to which a local surface energy is modified by the presence of a compositional gradient. The analysis predicts that both ductile and brittle fracture mechanisms are enhanced by the presence of a composition gradient. Special techniques to produce laboratory samples with microstructures which simulate the composition and microstructure gradients in solidified weld metal are used, along with appropriate mathematical models, to evaluate the properties of the composite weld metals. The composite modeling techniques are being applied to describe the effects of compositional and microstructural gradients on weld metal properties in Ni-Cu alloys. The development of metal matrix composition weld deposits on austenitic stainless steels has been studied. The particulate metal matrix composites were produced with ceramic or refractory metal powder filled cored wire, which was gas tungsten arc and gas metal arc welded.

Research Organization:
Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research
Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
FG02-87ER45308
OSTI ID:
6069967
Report Number(s):
DOE/ER/45308-5; ON: DE92005082
Country of Publication:
United States
Language:
English