Elastic and plastic deformation of surface asperities and their load-carrying mechanisms during the formation of a real contact area

Mitjan Kalin (Author), Blaž Brodnik Žugelj (Author), Martin Lamut (Author), Karim Hamouda (Author)

Abstract

How the contact behaviours of steel engineering surfaces with different roughnesses (R$_a$ = 0.1, 0.6 and 1.0 µm) are affected by the asperity work-hardening and the deformation regime are described here. Large values of the plasticity index Ψ between 20 and 50 indicate that all the surfaces should undergo a full plastic deformation. However, in the loading range up to the yield stress (on a nominal contact area) the rough surfaces exhibited at least 10 % elastic deformation, while for the smooth surfaces the elastic deformation was as much as 44 %. During the loading, the work-hardening increased the hardness of the rough surfaces by up to 63 %, and that of the smooth surfaces by up to 20 %. However, the asperities were able to carry the load that resulted in as much as a 4–10-times-higher contact pressure than the (initial) bulk yield strength. The proposed contact mechanisms for such an increased asperity-load-carrying capacity depend on the surface roughness. For the rough surfaces this is due to the work-hardening, while for the smooth surfaces the dominant mechanisms enhancing the load-carrying capacity are the work-hardening combined with the hydrostatic bulk stresses.

Keywords

in-situ asperity experiment;multi-asperity contacts;real contact area;work-hardening;deformation;steel;roughness;

Data

Language:	English
Year of publishing:	2023
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	539.92
COBISS:	129711619
ISSN:	0301-679X
Views:	1553
Downloads:	265
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	in-situ eksperimenti;kontakti več vršičkov;realna kontaktna površina;utrjevanje;deformacija;jeklo;hrapavost;
Type (COBISS):	Article
Pages:	str. 1-9
Volume:	ǂVol. ǂ178
Issue:	ǂpt. ǂA
Chronology:	Feb. 2023
DOI:	10.1016/j.triboint.2022.108067
ID:	17111295