Fatigue Crack Propagation and Fracture Toughness of Plasma Arc Welded Ti-6Al-4V Alloy
Abstract
Tensile, fracture toughness and fatigue crack propagation (FCP) data have been determined for a plasma arc weld (PAW) in 4mm thick Ti-6A1-4V alloy sheet. In addition, FCP data is reported for a weld in 9.6mm thick Ti-6A1-4V alloy produced by a PAW root weld and TIG filler runs. In all of the test pieces the stressing direction was normal to the welding direction. Fractures of across-weld tensile test pieces occurred in parent metal; the tensile strength of welded sheet was comparable with that of unwelded parent sheet. The fracture toughness of the welds was lower than that of unwelded parent sheet. The fracture toughness of the welds was lower than that of the parent metal due to the hard martensitic microstructure produced in the fusion zone as a result of the high post-weld cooling rates. FCP rates, for a given K, were slower in all the welded test pieces compared with parent material by factors of 5-15 for the 4mm thick sheet, and 3-7 for the 9.6mm thick material.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1985
- Accession Number
- ADA188075
Entities
People
- T. S. Baker
Organizations
- Royal Aircraft Establishment