A Combined Experimental Simulative Method for Studying the Material Bonding of Different Aluminum Alloys

There are several production techniques, such as extrusion or friction welding (both friction stir welding and linear friction welding), in which solid state material bonding takes place thanks to the very high pressure and temperature at which the materials are subjected. FEM analysis can be a valid tool to correctly forecast if bonding phenomenon really takes place and how process parameters influence the welding quality, based on a valid welding criterion implemented in the software. Amongst the several welding criteria, the attention was focused on the Piwnik and Plata model saying that the material bonding occurs when the ratio between the interface pressure and the effective stress acting in the material integrated along the time w, reaches a limit value wlim. In the present research the Authors extended their previous studies showing how this value depends on both material type and temperature proposing a procedure for the wlim identification based on a coupled experimental-simulative strategy. In particular, flat rolling experimental tests of sandwiches made of two rectangular specimens were considered for wlim calculation.