WCPM/CSCjointseminarContactandcavitation:Computermodels

fortribologicalprocessesLarsPastewka

KarlsruheInstituteforTechnology

Monday,27thFebruary,1p.m.D2.02Seminarroom,Engineering

Abstract:Tribologyisthescienceofmechanicalprocessesatmaterialsurfaces,suchasadhesion, frictionorwear.Studying these is complicatedbecausemost surfacesarerough, interactwith lubricants,waterorairandbecausethe interfacebetweentwomaterialsistypicallyinaccessibletoin-situexperimentaltechniques.Inthistalk,Igive examples of how computer simulations atmesoscopic and atomic scales canhelp to elucidate the processes that take place at these “buried interfaces”.Mesoscopic simulations of elastic contact and plastic contact between roughsurfaces allow a direct calculation of the area of intimate atomic contact [1].Conditionswithinthecontactingregionsaretypicallyextremeandgiverisetosevereplasticdeformation.Iwillthendescribesimulationsofinterfacialeffectsthatoccurintheregionof intimateatomiccontactduringshear.First, lubricantflowonsurfacessticking and slipping regions reveal how thematerial affects surface flow and thatstick/slip contrast can lead to cavitation within the lubricant [2]. Second, in theabsence of a lubricant, the sliding interface can accommodate shear by creatinginterfacialdislocationsthatcontroltheinterfacialstrengthofthematerial[3].

[1]Pastewka,Robbins,PNAS111,3298(2014);Appl.Phys.Lett.108,221601(2016)[2]Savio,Pastewka,Gumbsch,ScienceAdvances2,e1501585(2016)[3]Sharp,Pastewka,Robbins,Phys.Rev.B93,121402(R)(2016)

Abuffetlunchisavailablefrom12:45pm.

Moreinfo:http://warwick.ac.uk/wcpm/seminars