Recent developments in small-angle X-ray scattering for the study of metals and polymers

New applications of Small-Angle X-ray Scattering, in Materials Science of m etallic alloys and polymers are presented. The use of powerful X-ray source s like synchrotrons is shown to enable in-situ study of dynamic system chan ges. Examples are given in welding of precipitation hardening aluminium all oys, where precipitate microstructures in welded structures are studied wit h high resolution and simulated through non-isothermal heat treatments. The interest of in situ measurements is also shown for polymeric systems. Demi xion phenomena occuring in the DGEBA/MCDEA/PEI modified thermoset system fa r from the critical concentration is studied during the curing of the epoxy -amide polymerization. A methodology showing evidence of a nucleation/growt h mechanism is presented. In addition, scattering, measurements during defo rmation of polyethylenes is shown to yield the density of tie molecules, th at are in direct relation to their long term properties.