The paper describes a new approach to characterize metallic materials by a novel instrumented notch impact test for samples with small specimen size. A piezo‐electric sensor mounted on the pendulum hammer provides force information during the fracture process. By numerical integration of the signal the absorbed impact energy can be calculated very exactly. Further information about the fracture behavior can be extracted from the resulting force‐displacement‐diagram. Several duplex stainless steels in different heat treatment conditions were tested and compared to standard Charpy impact testing specimen. It is concluded that different grades of embrittlement of duplex materials can be detected with high accuracy. Due to a data acquisition rate of 250 kilo‐samples/second and limited stiffness of the pendulum hammer impact energies of less than 7% of maximum energy materials with high brittleness can only be characterized qualitatively.

Oxide dispersion strengthened (ODS) superalloys are generally considered to be promising candidate materials for high-temperature applications up to 1300 C because of their favorable combination of a highly elongated, coarse grain structure with dispersion strengthening by incoherent, fine, and homogeneously distributed Y 2 O 3 particles. [1] In particular, the creep behavior of the recently developed bcc ironbased ODS superalloy, PM 2000, and its British counterpart, MA 956, reveals partly contradictory and surprising results, which have not yet been clarified in the literature. [2±10] As an example, Figure 1 shows the true stress±true strain curves obtained from tensile specimens of PM 2000 at 1000 C. The material used in this study exhibits a grain structure typical of ferritic ODS superalloys. [5][6][7][8] Within the gauge length it consists merely of four large elongated grains oriented in the hard <111> orientation. [10] Beyond the elastic limit, the point of maximum deformation resistance (or maximum flow stress) is passed before the 0.2 % yield stress (see the dashed line) is attained, indicating an absence of work hardening. Secondly, a drastic decrease of s with increasing e follows, which is even more pronounced for lower strain rates, é. Consequently, strain-to-failure values of less than 1 % have been reported in long-term creep experiments. [7] This dramatic reduction of creep strength is accompanied by localized crystallographic shear deformation covering only a small fraction of the total gauge length of the specimen, see the macrograph (Fig. 2) after a plastic elongation of 1.5 % at é = 4´10 ±7 s ±1

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