TY  - JOUR
AU  - Tsybenko, Hanna
AU  - Tian, Chunhua
AU  - Rau, Julia
AU  - Breitbach, Benjamin
AU  - Schreiber, Paul
AU  - Greiner, Christian
AU  - Dehm, Gerhard
AU  - Brinckmann, Steffen
TI  - Deformation and phase transformation in polycrystalline cementite (Fe3C) during single- and multi-pass sliding wear
JO  - Acta materialia
VL  - 227
SN  - 1359-6454
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2022-02739
SP  - 117694 -
PY  - 2022
AB  - Cementite (Fe3C) plays a major role in the tribological performance of rail and bearing steels. Nonetheless, the current understanding of its deformation behavior during wear is limited because it is conventionally embedded in a matrix. Here, we investigate the deformation and chemical evolution of bulk polycrystalline cementite during single-pass sliding at a contact pressure of 31 GPa and reciprocating multi-pass sliding at 3.3 GPa. The deformation behavior of cementite was studied by electron backscatter diffraction for slip trace analysis and transmission electron microscopy. Our results demonstrate activation of several deformation mechanisms below the contact surface: dislocation slip, shear band formation, fragmentation, grain boundary sliding, and grain rotation. During sliding wear, cementite ductility is enhanced due to the confined volume, shear/compression domination, and potentially frictional heating. The microstructural alterations during multi-pass wear increase the subsurface nanoindentation hardness by up to 2.7 GPa. In addition, we report Hägg carbide (Fe5C2) formation in the uppermost deformed regions after both sliding experiments. Based on the results of electron and X-ray diffraction, as well as atom probe tomography, we propose potential sources of excess carbon and mechanisms that promote the phase transformation.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000792706700010
DO  - DOI:10.1016/j.actamat.2022.117694
UR  - https://juser.fz-juelich.de/record/908650
ER  -