Abstract: A nickel-chromium-based brazing alloy has a composition consisting essentially of about 9.5 to about 16.5 atom percent chromium, 0 to about 5 atom percent iron, about 10 to about 15 atom percent silicon, about 6 to less than 7 atom percent boron, and 0 to about 5 atom percent molybdenum, the balance being essentially nickel and incidental impurities. The alloy is especially suited for use as a brazing filler metal for joining stainless steel and/or superalloy at temperatures above 1100 degree(s) C. Such a filler metal has a thickness ranging from about 65 to 100 micrometers and a width ranging from 100 to 250 millimeters and more. Honeycomb structures and thin corrugated fin/plate structures particularly suited for use in manufacture of plate-type heat exchangers formed at least in part from stainless steels and/or superalloys are brazed using a unique process. The process is characterized by a long holding time at brazing temperature, and combines brazing and diffusion annealing in one technological step.