Modern stationary gas turbines are designed for the best possible efficiencies and outputs. However, as temperatures and stresses are increased, the design and manufacture of cooled blading in gas turbines becomes complex. This results in higher costs and longer delivery times for cast components and it becomes worthwhile to repair damaged components. The microstructure of samples processed by liquid phase diffusion sintering of pre-alloyed atomized and mixed powders is investigated by electron microprobe analysis, X-ray diffraction and optical microscopy involving colour metallography. The melting and remelting behaviour is analysed by differential thermal analysis. Materials obtained from powders based on the cast superalloys NIM-75, IN-939 and IN-738LC and the braze materials based on the systems Ni-Cr-B, Ni-Cr-Fe-Si-B are shown to consist of a dispersion of borides and/or silicides in the base metal matrix and a more or less eutectic grain boundary precipitation depending on the thermal cycle and the composition. The porosity exhibited does not exceed that of the cast base materials IN-738LC and IN-939. The thermal fatigue proved to be excellent. The corrosion resistance was only sufficient in blends with a high chromium content as boride precipitation caused chromium depletion. Liquid phase diffusion sintering meets in many cases the requirements of repairing cracks and erosion damage by filling and sintering with a braze mix consisting essentially of a superalloy base material and a braze component containing a melting point depressant.