Device and method for the amelioration of recesses

A device for the amelioration of a recess, in a porous, perforate material having cavities freed by the recess, said device comprising

• an element for generating or coupling in mechanical energy, and a cylindrical collar with cylindrical jacket surface having an external diameter and having a central recess for receiving a guide pin,
• wherein the guide pin is provided to be inserted substantially as far as the bottom of the recess before mechanical energy is applied, wherein the guide pin, in the area of the end thereof directed toward the bottom of the recess, is surrounded by an amelioration sleeve made from a material that can be liquefied by mechanical energy, wherein the cylindrical jacket surface of the amelioration sleeve has substantially the same external diameter as the collar, and wherein the guide pin is received movably in the central recess such that, when mechanical energy is applied, the collar can be moved relative to the guide pin in the direction toward the bottom of the recess while liquefying and laterally and/or longitudinally displacing the material of the amelioration sleeve wherein the cylindrical collar has a circular cylindrical jacket surface, and the amelioration sleeve has a circular cylindrical jacket surface, and wherein the external diameter of the collar and of the amelioration sleeve are substantially the same as the internal diameter of the recess to be ameliorated, and
• wherein the collar, at its distal end, has a circumferential distal edge tapering toward said distal end, wherein this distal edge is
• either straight, and therefore conical,
• or curved, namely concave or convex,
• or has a radially stepped design at the distal end, wherein the circumferential distal edge is arranged at the step transition,
• and wherein the amelioration sleeve is a simple hollow cylinder.