Nanotribological characterization of advanced tool steels

Abstract:    Tribological  problems  of  tool–work  piece  interaction  is  a  key  aspect  influencing  product quality,  process  performance  and  tool  lifetime.  For  example,  in  sheet  metal  forming operations, sliding contact may cause adhesive wear of sheet materials with build up of worn material on the tool surface. This tribological problem often resulted in loss of tolerance and product quality and is called galling.      It  was  demonstrated  that  tendency  to  adhesive  wear  depends  on  the  steel  grade,  which means high importance of chemical- and phase-constitution of the tool steel. It was suggested that  adhesion  to  the  matrix  is  critical  due  to  metal  to  metal  contact  while  carbide  phase prevent adhesion of conterbody materials. Nevertheless, in macroscale tests it is difficult or even impossible to separate contribution of each phase into the wear mechanism.       In the present work, selected steels are to be investigated  at nanoscale by means of AFM facilities. Main attention will be paid on adhesion and frictional properties of steel matrix and primary  phase.  As  expected  and  reported  in  several  articles,  carbides,  carbonitrides  and nitrides   may   behave   differently,   contributing   into   the   final   performance   differently. Additional  attention  will  be  paid  on  phase  size  and  distribution,  meaning  they  are  also important parameters influencing tribological behaviour.