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Author Cox, A. ♦ Zorko, S. ♦ English, C.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ ALUMINIUM ALLOYS ♦ RESISTANCE WELDING ♦ COMPOSITE MATERIALS ♦ SILICON CARBIDES ♦ TITANIUM BASE ALLOYS ♦ VANADIUM ALLOYS ♦ FRACTURE PROPERTIES ♦ HEAT AFFECTED ZONE ♦ MICROSTRUCTURE ♦ ALLOYS ♦ CARBIDES ♦ CARBON COMPOUNDS ♦ FABRICATION ♦ JOINING ♦ MATERIALS ♦ MECHANICAL PROPERTIES ♦ SILICON COMPOUNDS ♦ TITANIUM ALLOYS ♦ WELDING ♦ ZONES 360601* -- Other Materials-- Preparation & Manufacture
Abstract Solid-state and fusion welds have been produced between sheets of monolithic and SiC fiber-reinforced Ti-6Al-4V using capacitor discharge resistance spot welding. Solid-state welds in monolithic sheet were characterized by beta grain growth across the weld interface, an alpha-prime martensite microstructure and the presence of occasional, fine interface discontinuities. Despite experiencing tensile-shear fracture along or directly adjacent to the weld interface, average tensile-shear fracture along or directly adjacent to the weld interface, average tensile shear strengths for optimized solid-state welds were comparable to those of conventional fusion spot welds produced at higher energy inputs which failed by nugget pullout. High integrity, solid-state welds were also produced in Ti-6Al-4V sheet containing 35 vol-% continuous SiC (SCS-6) fibers. Under optimized conditions, defect-free solid-state welds were produced which exhibited negligible evidence of fiber displacement or degradation. The weld zone was characterized by limited beta grain growth across the interface and a fine, martensitic microstructure. The average tensile shear strength for these welds was approximately 60% of the exhibited by optimized solid-state welds produced in the monolithic material. This strength reduction was attributed primarily to the initiation of tensile shear fracture in the vicinity of the weld outer periphery notch and propagation either along the fiber/matrix interface in the heat-affected zone (HAZ) directly adjacent and parallel to the weld interface or transverse through the sheet, in both cases remote from the weld interface.
ISSN 00432296
Educational Use Research
Learning Resource Type Article
Publisher Date 1993-10-01
Publisher Place United States
Journal Welding Journal
Volume Number 72
Issue Number 10


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