Cold welding and fretting tests on quasicrystals and related compounds

This paper reports a vacuum or space related effect, which is referred to as “cold welding”, “adhesion” or “sticking”. This effect is studied for bulk quasicrystal (J.M. Dubois, Useful Quasicrystals (World Scientific, Singapore, 2005)) versus different kinds of counterparts (steel, aluminium, titanium, hard metals). Full series of samples, prepared either by crystal-pulling techniques (single crystals) or by sintering (multi-grain samples) were analysed by fretting tests. Four alloy systems were investigated: Al–Pd–Mn, Al–Cr–Fe–B, Al–Cu–B and Al–Cu–Fe–B, with different crystallographic structures and nominal compositions. These materials, especially icosahedral phases, exhibit the absence of cold-welding in vacuum versus certain steels.