TiNi alloys are potentially able to include in their structure a significant quantity of hydrogen which allows them to be used as electrodes in hydrogen batteries providing their electrical characteristics are suitable. TiNi alloys were produced in hyperquenched tape shape. These tapes were then electrolytically hydrided. X-ray analysis of hydrided and nonhydrided samples was performed. In the hyperquenched tape the B2 and the ‘R’(H) phases, the presence of which is linked to the hyperquenched constraints, coexist. The hydrided electrolytically hyperquenched tape has the TiNiHx (x=0.3) formula and contains the two hydrided forms corresponding to those that are unhydrided. At around 100°C, under hydrogen gas, the quadratic hydride parent of B2 remains alone. The TiNiH0.3 sample has been analysed using differential calorimetry under argon and hydrogen gas. In the cubic structure only two octahedral sites are occupied by hydrogen. In TiNiH0.3 only the smaller octahedral sites are occupied by electrolytic hydrogen. If TiNiH0.3 is then charged with hydrogen gas, this gas occupies the other larger octahedral site. The hydride has the formula TiNiH0.85.
L'alliage TiNi est un mate´riau potentiellement apte au stockage d'hydroge`ne. Produit sous la forme de rubans hypertrempe´s, il a e´te´ hydrure´ e´lectrolytiquement et analyse´ par RX tout comme les e´chantillons non hydrure´s. Les rubans hypertrempe´s contiennent les phases B2 et “R”(H), la pre´sence de cette dernie`re e´tant lie´e aux contraintes de l'hypertrempe. Les rubans hydrure´s e´lectrolytiquement ont pour composition TiNiH0.3 et ils renferment deux formes d'hydrures correspondant aux deux formes non hydrure´es B2 et “R”(H). Vers 100°C sous hydroge`ne gaz l'hydrure quadratique parent de B2 subsiste seul. TiNiH0.3 a e´te´ analyse´ par calorime´trie diffe´rentielle (DSC) sous argon et hydroge`ne gaz. Dans la structure cubique seuls deux sites octae`driques peuvent e^tre occupe´s par l'hydroge`ne. Dans TiNiH0.3 l'hydroge`ne e´lectrolytique n'occupe que les sites les plus petits. Si, au cours d'un cycle DSC, TiNiH0.3 est charge´ par de l'hydroge`ne gaz celui-ci remplit les sites les plus grands. L'hydrure a alors pour formule TiNiH0.85.