Process for crushing or pulverizing a shape memory alloy or a superelastic alloy of nickel and titanium comprises converting the starting alloy into a brittle hydride, crushing or pulverizing, optionally sieving, and heat treating

摘要

Crushing or pulverizing a shape memory alloy or a superelastic alloy of nickel and titanium, optionally with additional alloying partners comprises converting the starting alloy electrochemically as the cathode into a brittle hydride in an electrolytic process releasing hydrogen; mechanically crushing or pulverizing the hydride; optionally sieving the hydride during and/or after crushing or pulverizing; driving or pumping off the hydrogen in a reaction vessel by heating the crushed or pulverized hydride; and heat treating the crushed or pulverized hydride. The temperature in the reaction vessel and in the heat treatment step can reach the maximum temperature of the solid starting alloy (approximately 1240 [deg] C). Preferred Features: The starting alloy is located during the electrolytic process in a network or lattice made from a gold alloy which assures an electrical connection to the alloy even if the starting alloy consists of several pieces or breaks into several pieces during the electrolytic process.