Two ways of looking at the intermediate position of binary alloys - pulse heating results of NiCr and CuNi alloys

Full text: The measurements of NiCr and CuNi alloys show two examples to interpret binary alloys: at one hand to study selected properties while changing the concentration of the respective pure constituents (phase diagrams are the paradigm of this first approach). At the other hand, binary alloys have an intermediate position between pure elements and highly alloyed materials as used for industrial applications. Five CuNi alloys have been investigated to follow the first considerations - this might be called a 'horizontal approach'. A 'vertical approach' has been exercised on Ni80Cr20, which is set in context to its pure constituent elements and to the highly alloyed material Inconel 718. The two approaches are not new at all, but they are a starting point to test the performance of fast pulse-heating when being applied to simple and more complex alloys. The high heating rates, which are characteristic for this kind of experiments, influence the solid - liquid phase transition in contrast to phase diagrams which are obtained at thermodynamic equilibrium. Preliminary results on CuNi alloys show good agreement to data measured under quasi static conditions in levitation experiments, which indicates that the loss of thermodynamic equilibrium does not necessarily lead to big deviations. (author)