SwePub
Sök i LIBRIS databas

  Utökad sökning

(WFRF:(Rosen Anders))
 

Sökning: (WFRF:(Rosen Anders)) > Tribological and Me...

  • Ghasemi, Rohollah,1983-Jönköping University,JTH. Forskningsmiljö Material och tillverkning – Gjutning,Department of Mechanical Engineering, Materials and Manufacturing—Casting, School of Engineering, Jönköping University, Sweden (författare)

Tribological and Mechanical Behaviour of Lamellar and Compacted Graphite Irons in Engine Applications

  • BokEngelska2015

Förlag, utgivningsår, omfång ...

  • Jönköping :School of Engineering, Jönköping University Department of Materials and Manufacturing,2015
  • 49 s.
  • electronicrdacarrier

Nummerbeteckningar

  • LIBRIS-ID:oai:DiVA.org:hj-25724
  • ISBN:9789187289064
  • https://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-25724URI
  • https://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-22011URI

Kompletterande språkuppgifter

  • Språk:engelska
  • Sammanfattning på:engelska

Ingår i deldatabas

Klassifikation

  • Ämneskategori:vet swepub-contenttype
  • Ämneskategori:lic swepub-publicationtype

Anmärkningar

  • There has been much discussion about the beneficial uses of lamellar graphite iron in piston rings–cylinder liner systems, where a good combinations of both thermal and tribological properties are essential. The excellent tribological performance of lamellar iron under such sliding conditions is principally associated with lubrication behaviour of the graphite particles which are distributed as lamellas throughout the matrix. During sliding, graphite particles are extruded and smeared onto the counterfaces, act as solid lubricating agents and form a thin graphite film between the sliding surfaces. Although this process especially, during the running-in period significantly changes the sliding wear response of the components, the exact mechanism behind of this phenomenon has rarely been discussed in previous studies.It is tribologically beneficial to keep the graphite open, particularly in applications where the scuffing issues do matter. In this thesis, the main causes involved in closing the graphite lamellas are discussed, with a focus on matrix plastic deformation that occurs during sliding. In first step, the relationship between graphite lamellae orientation and plastic deformation was investigated. To do so, two piston rings, belonging to the same two-stroke marine engine operated for different periods of time, were selected and compared to the unworn sample. The worn piston rings displayed a substantial decrease in both frequency and area fraction of the graphite lamellas. Most of the lamellas were closed as a result of plastic deformation of matrix. This happening was caused mainly by the interaction between abrasive particles and metallic matrix. Additionally, it was found that graphite lamellas parallel or near-parallel to the sliding direction exhibited maximum closing tendency under sliding condition.In next step, to have a better understanding of the graphite film formation mechanism and matrix deformation role in closing the graphite lamellas, microindentation and microscratch testing were performed on typical lamellar iron. The qualitative results showed a similar mechanism involving in graphite contribution to lubricate the sliding surfaces. Moreover, microindentations made nearby the graphite lamellas demonstrated that the deformation of the matrix causes the formation of cracks in the centre of the graphite lamellas, compressing and then extruding the graphite from its natural position, irrespective of the lamellas′ size. Furthermore, it was found that subsurface graphite orientation had a large influence on the extrusion behaviour, in that, for graphite lamellas oriented towards the indenter, the effect was observed more pronounced.Furthermore, an improved fully ferritic solution strengthened compacted graphite iron was produced for future wear studies. The effects of different Si levels and section thicknesses on tensile properties and hardness were investigated as well. The influence of Si content and section thickness on mechanical properties was revealed by improving the materials strength and slightly enhancing the hardness through increasing Si content. Besides, Si addition up to 4.5 wt% significantly affected the strength and elongation to failure of cast samples.

Ämnesord och genrebeteckningar

Biuppslag (personer, institutioner, konferenser, titlar ...)

  • Professor, Anders,JarforsJönköping University,JTH. Forskningsmiljö Material och tillverkning – Gjutning(Swepub:hj)JARAND (preses)
  • Assistance professor, Lennart,ElmquistJönköping University,JTH. Forskningsmiljö Material och tillverkning – Gjutning(Swepub:hj)ELLE (preses)
  • Rosén, Bengt-Göran,ProfessorHalmstad University (opponent)
  • Jarfors, Anders,ProfessorDepartment of Mechanical Engineering, Materials and Manufacturing—Casting, School of Engineering, Jönköping University, Sweden (preses)
  • Elmquist, Lennart,Assistance professorDepartment of Mechanical Engineering, Materials and Manufacturing—Casting, School of Engineering, Jönköping University, Sweden (preses)
  • Jönköping UniversityJTH. Forskningsmiljö Material och tillverkning – Gjutning (creator_code:org_t)

Internetlänk

Hitta via bibliotek

Till lärosätets databas

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy