Platinum Metals Review - Volume 39, Issue 4, 1995

Recent discoveries in the biological sciences have revealed that nitric oxide has a number of important physiological functions and is also implicated in a number of diseases. This realisation has provided a stimulus for nitric oxide related drug research and development. In this review new work aimed at the development of potential therapeutic use of ruthenium compounds, particularly ruthenium(III) polyaminocarboxylate, JM1226, is presented and discussed in the context of the chemistry and biology of nitric oxide. Based on these studies, prospects for the further development of JM1226 appear promising.

The effect of adding very small amounts of yttrium and zirconium to platinum alloys has been investigated. The results indicate that a platinum alloy which contains bath elements has a higher recrystallisation temperature and superior mechanical properties than a platinum alloy containing only zirconium. In addition, the platinum alloy which contains both yttrium and zirconium has a stable structure in which regular second phases have been found both in the grains and on the grain boundaries.

Martensitic transformations in equiatomic titanium-nickel and titaniumnickel based alloys are of interest because they are associated with the shape memory effect. Equiatomic titanium-nickel, which possesses such superior mechanical properties as high strength, elevated ductility and corrosion resistance, is the most important of several shape memory alloys. Here, the character of the martensitic transformalion in equiatomic titanium-nickel alloy with some of the nickel replaced by ruthenium is discussed. Data are presented on the temperature of the transformation upon heating and cooling, the transformation sequence and the stabilisation of the high temperature phase in TiNi-TiRu alloys, using electrical resistance, thermal expansivity and differential thermal analysis between ~300°C and liquid nitrogen temperatures. Alloys which contained 0.5 to 2 atomic per cent ruthenium were found to undergo a two stage transformation, while the high temperature phase in titanium-nickelruthenium, which has B2-type crystal structure, was stabilised by the addition of 2 atomic per cent ruthenium.