LASER AND ELECTRON-BEAM ALLOYING OF AL WITH FE AND SN

Low hardness and tendency to galling are among the main limitations of light alloy applications for friction joints fabrication. Laser and e lectron beam action on multilayer coatings predeposited on Al substrat e were examined as a method to make an alloy containing Fe (as a harde ning element) and Sn (as a solid lubricant). The original method was p roposed for coating deposition. Al substrate is covered by thin films of pure metals (Fe and Sn). Pressing of this system allows access to a good mechanical contact between 'coating-coating' and 'coating-substr ate'. The results of treatment (modified zones structure, doping eleme nt distribution, microhardness) by continuous wave CO2 laser, pulse-pe riodic Nd:YAG laser and electron beam were compared and analysed. The possibility of reaching uniform distribution of Fe (concentration 24-2 6 wt%) and Sn (concentration 5-7 wt%) after CO2 laser and electron bea m action is promising for potential industrial application of the prop osed alloying method.