Anisotropic Fatigue Crack Propagation in Titanium Aluminide TiAl with Lamellar Microstructure.

The Effect of Microstructure on Fracture Toughness and Fatigue Crack Growth Behavior in g-Titanium Aluminide Based Intermetallics

Ambient-temperature fracture toughness and fatigue crack propagation behavior are investigated in a wide range of (g 1 a2) TiAl microstructures, including single-phase g, duplex, coarse lamellar (1 to 2 mm colony size (D) and 2.0 mm lamellar spacing (l)), fine lamellar (D ; 150 mm, l 5 1.3 to 2.0 mm), and a powder metallurgy (P/M) lamellar microstructure (D 5 65 mm, l 5 0.2 mm). The influences ...

Effects of Microstructure on Room Temperature Fatigue Crack Initiation and Short Crack Propagation in Udimet

An assessment of the effects of microstructure on room temperature fatigue crack initiation and short crack propagation in a Ni-base superalloy is presented. The assessment was carried out on microstructural variants of U720Li, including as-received U720Li, U720Li-LG (large grain variant) and U720Li-LP (large intragranular coherent γ′ variant). Fatigue tests were carried out at room temperature...

FATIGUE THRESHOLDS OF CRACKS RESULTING FROM IMPACT DAMAGE TO �-TiAl

Significant research has been conducted in recent years on the �-based titanium aluminide alloys. The low density of �-TiAl relative to current nickel-based superalloys, has made it an attractive candidate for use in the low-pressure turbine blades of gas turbine engines [1]. In addition to weight savings, the lower density leads to higher specific stiffness and good high temperature strength r...

Fatigue crack propagation in microcapsule - toughened epoxy

The addition of liquid-filled urea-formaldehyde (UF) microcapsules to an epoxy matrix leads to significant reduction in fatigue crack growth rate and corresponding increase in fatigue life. Mode-I fatigue crack propagation is measured using a tapered doublecantilever beam (TDCB) specimen for a range of microcapsule concentrations and sizes: 0, 5, 10, and 20% by weight and 50, 180, and 460 lm di...

High Temperature Fatigue Crack Propagation in INCONEL718