Abstract: Process for producing very pure platinum materials dispersion-reinforced with Y.sub.2 O.sub.3 and having high strength and extensibility, even in the temperature range >800.degree. C., from platinum powder by mechanical alloying, which comprises the process stepspreparing platinum powder of high purity and low particle size of from 2 to 10 .mu.m,introducing and dispersing Y.sub.2 O.sub.3 particles >1 .mu.m in the platinum powder by milling in a platinum vessel using milling media of zirconium oxide,degassing the milled product under a vacuum of better than 10.sup.-3 mbar and with an increase in temperature to at least 1200.degree. C. in a platinum capsule for a period of up to 48 hours,gastight welding of the evacuated capsule and hot isostatic pressing at 1350.degree. C.