High-strain, high-strain-rate deformation of tantalum and tantalum-tungsten alloys

Experimental results and constitutive modelling for tungsten and tantalum at high strain rates and very high temperatures

Recently reported results of the high strain rates, high temperature measurements of the yield stress of tungsten and tantalum have been analyzed. The highest temperature reached in the experiment, based on heating and stressing a thin wire by a fast, high current pulse, was 2250 C and 2450 C, for tantalum and tungsten, respectively. The strain-rates in both the tungsten and tantalum tests were...

Growth and Collapse of Nanovoids in Tantalum Monocrystals Loaded at High Strain Rate

Shock-induced spall in ductile metals is known to occur by the sequence of nucleation, growth and coalescence of voids, even in high purity monocrystals. However, the atomistic mechanisms involved are still not completely understood. The growth and collapse of nanoscale voids in tantalum are investigated under different stress states and strain rates by molecular dynamics (MD) simulations. Thre...

Temperature and strain-rate dependence of the flow stress of tantalum single crystals in cyclic deformation

The influence of tungsten alloying on the mechanical properties of tantalum

In mechanical tests of tantalum-tungsten alloys with nominal tungsten contents between 0 and 10 wt% for strain rates between 0.000016 and 6800 sr and temperatures between 77 and 400 K, the addition of tungsten noticeably reduces the strain-rate dependence of the flow stress of tantalum near yield. It also subtly alters the strain-rate behavior of the work hardening, making it more like that of ...

High strain rate properties of metals and alloys

The high strain rate dependence of the flow stress of metals and alloys is described from a dislocation mechanics viewpoint over a range beginning from conventional tension/compression testing through split Hopkinson pressure bar (SHPB) measurements to Charpy pendulum and Taylor solid cylinder impact tests and shock loading or isentropic compression experiment (ICE) results. Single crystal and ...