Effects of in-situ processing methods on the microstructure and fracture toughness of V-V(sub 3)Si composites

摘要

This paper describes ductile-phase roughening in V-V(sub 3)Si in-situ composites produced by conventional arc melting (AM), cold-crucible induction melting (IM), and cold-crucible directional solidification (DS). Notched three-point bending tests were performed to determine the effects of synthesis method on the room temperature fracture toughness of eutectic compositions, which contain nearly equal volume fractions of V(sub 3)Si and the V(Si) solid solution phase. Fracture toughness values ranged from 10 MPa(radical)m for the AM eutectic to over 20 MPa(radical)4m for the IM and DS eutectic alloys. SEM fractography, surface profiling, and chemical analyses were performed to correlate the toughness values with the microstructures and interstitial concentrations produced by the three synthesis methods.