Since the invention of Friction Extrusion (FE), it has been of minor interest for materials research, since there has been no equipment to explore its commercial exploitation.
Those days are over now.
Conventional extrusion of metals has been around for a long time. Typically, a metal billet is heated and pressed through a die with some shape, producing stock for a multitude of applications.
Extruded materials are often stretched to straighten the material and to increase the yield strength and then aged to improve ultimate strength.