## 1 Introduction
This means, that even without external heating of the semi-finished parts, a high-speed forming process is carried out at a higher temperature compared with a quasistatic process, which can lead to significant thermal softening of the material. This is especially relevant when it comes to localization and a correspondingly strong increase in the local strain, strain rate, and temperature. An exemplary application where this effect becomes relevant is the formation of adiabatic shear bands in high-speed impact cutting [14]. The two effects of strain hardening and thermal softening superpose each other so that accurate and thermo-mechanically consistent material modeling is complicated significantly. As part of previous work [15], a method was developed for the determination of material and failure characteristics for processes with high forming speeds including extremely high strain rates in the range of more than \(10^{4}\)/s, using DC06 steel and AW5754 aluminum alloy as examples. The calculation of the values was performed by testing samples of different stress states, using an electromagnetically accelerated hammer and following inverse simulation of the process. An interesting observation from this study is a significantly higher strain rate sensitivity of tensile specimens compared with shear specimens in the case of DC06 steel. However, as temperature has been disregarded in the inverse parameter identification, adiabatic heating is not considered, which leads to an overestimation of the stresses and a simultaneous underestimation of the strains. Additionally, it must be taken into account that due to the strong localization of the strains and the temperature increase, the meshing significantly affects the accuracy of the simulation. With increasing element size, temperature peaks can no longer be modeled correctly, which leads to a significant underestimation of the occurring temperature [16; 17; 18]. The topic of local temperature change in the deformation zone during uniaxial tension has always been extremely important and in the early stages could be obtained using analytical calculations and simplified models [19]. Later in [20], the effects of initial geo metrical defects and thermal gradients on the tensile stress and strain behavior in FEM simulations of uniaxial tensile tests were investigated. Thus, the temperature calculation in the deformation region is based on the measurement of the plastic work fraction and its subsequent conversion into heat (also referred to as the inelastic heat fraction (IHF)). In [21], also using the example of a uniaxial test bar, it was proved that the IHF is not constant depending on the plastic strain, and in addition, is also sensitive to changes in the strain rate. In the study [22], monotonic loading in uniaxial tension tests was investigated using a digital image correlation system in conjunction with infrared thermography. However, this study was only carried out for relatively lower strain rates. Altogether, the development and change of temperature in the fracture region of a material is extremely important and can explain many of the effects occurring in the material, often considered as an effect of the strain rate. These two important concepts, temperature and strain rate dependence, are fundamental for the creation of a material model that is close to the real process. In the area of high strain rates, everything is much more complicated because measuring equipment is restricted with regard to measuring frequency and the area where the local temperature maximum is reached shortly before the material fracture is relatively small. Thus, the main goal and motivation of this work are to provide a deeper understanding of the superposing and opposing influences of strain rate and temperature on the material behavior in high-speed forming by quantifying the adiabatic heating of the workpiece during deformation and failure under high-speed loading. For this purpose, uniaxial tensile tests at different high strain rates are analyzed experimentally and numerically.