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The effect of preparation conditions on the relative elongation of nickel foams prepared by electrodeposition technology has been studied. The relative elongation is hardly in uenced by sintering in NH 3 decomposition atmosphere at 980°C for 40 min, by burning in air at 600°C for 4 min beforehand, or by lowering the sintering temperature to 850°C. With regard to conductive treatment, the relative elongation is signi cantly higher for chemically plated Ni than for coating by graphite base conductive colloid.MST/5661

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During high-temperature oxidation, the aluminide coating degrades by two mechanisms, one is the oxidation of the outer surface, and the other is Al diffusion into the substrate. The relevant laws are investigated for coatings on Co-base superalloys oxidised in air at high temperatures. The driving force mainly comes from the oxidation reaction for the outer degradation layer, and the chemical potential for the inner degradation layer. By an approximation approach, it can be concluded that the life of the outward-diffusion coating is roughly directly proportional to the second power of the main-phase thickness of the coating.Wa Èhrend Hochtemperaturoxidation kann die Aluminidbeschichtung durch zwei Mechanismen gescha Èdigt werden; der eine ist die Oxidation der a Èuûeren Oberfla Èche und der andere ist die Al-Diffusion in das Grundmaterial. Fu Èr Beschichtungen auf Co-basierenden Superlegierungen, die in Luft bei hohen Temperaturen oxidiert wurden, sind die relevanten Gesetze untersucht worden. Die Triebkraft kommt im wesentlichen von der Oxidationsreaktion fu Èr die gescha Èdigte a Èuûere Schicht und vom chemischen Potential fu Èr die gescha Èdigte innere Schicht. Mit Hilfe eines Na Èherungsansatzes kann gefolgert werden, dass die Lebensdauer der nach auûen diffundierenden Beschichtung in etwa direkt proportional der zweiten Potenz der Dicke der Hauptphase der Beschichtung ist. Materials and Corrosion 54, 93±96 (2003) High-temperature oxidation of aluminide coatings 93

The effect of Ti on the aluminide coating has been investigated for a new Co‐base superalloy DZ40M. The results showed that the addition of Ti into aluminiser could reduce the permeation of Al into the substrate, and quicken the oxidation and degradation of the coating.

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