Deformational heating at the crack tip and its role in fracture of Ti-10V-2Fe-3Al
The anomalous behavior of certain titanium alloys at high rates of deformation has caused an interest in the fundamental aspects of high-strain-rate fracture and the role of deformational heating in the fracture process. The commercial metastable beta-titanium alloy Ti-10V-2Fe-3Al was subjected to a series of mechanical tests at various loading rates. Tensile tests were performed over a range of strain rates from quasi-static (10/sup -3/ s/sup -1/) to near ballistic (10/sup 3/ s/sup -1/), requiring the development of a high-speed data-acquisitioning system. Fracture-toughness determinations were made through K/sub IC/ testing, the loading rate being varied over four orders of magnitude. The computerized data-acquisition system allowed for the determination of crack tip velocity, as well as load and loading-rate parameter. The expected increase in flow stress and ultimate tensile strength with increasing strain rate was paired with the unusual trend of increased total elongation and reduction of area at higher strain rates. The fracture toughness was seen to increase 82% with a four-order-of-magnitude increase in loading rate. Earlier fractographic studies had revealed a dramatic change in fracture surface topography with strain rate, indicative of a changing fracture mechanism.
- Research Organization:
- Virginia Univ., Charlottesville (USA)
- OSTI ID:
- 6715582
- Country of Publication:
- United States
- Language:
- English
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