oa A Comparison of the Microstructure and Corrosion of cp-Ti and Ti-6Al-4V Alloys Modified with Pd and Ru and Processed by Powder Metallurgy

Adding low levels of Pd, Ru and other platinum group metals to titanium and its alloys is an effective way of increasing their corrosion resistance in a range of media, particularly reducing acids [1-5]. The approach has also been shown to be successful improving resistance to crevice corrosion [6-11]. As a result, a number of commercial grades are specified in the ASTM standards, mostly based on based on Pd and Ru additions to commercial purity cp-Ti and Ti-6Al-4V grades. The development of the Ru grades (e.g. Grades 26 and 29) [12-17] was motivated by the high cost of Pd and the impact this had on the price of the Pd-containing grades. Furthermore, the proven ability to use two noble metal-modified alloys helps developers overcome cost issues caused by ever-fluctuating noble metal prices.