Sclero-topometry in superficial wear and metal processing of ductile cast iron at boundary lubrication. Application to tribological valorization of waste oil

摘要

During the time, the specific characteristics and the efficient lifetime of oil progressively decrease, due to complex pollution, ultimately making the oil unsuitable for the initial applications. Regenerated transformers oils are only used today for concrete formwork. The strategy to regenerate and to valorise waste transformer oils in metal forming is investigated using improved combinations of sclerometric and topometric tests on ductile cast iron. Tribo-abrasive tests are performed in critical conditions, with base oil, waste oil and regenerated oil, of similar viscosities in order to discriminate their interfacial performances. The forms of the scratch traces indicate wear resistance and tendency to elasto-plastic deformation. The mechanisms of deformation and frictional behaviours were evaluated using optical and Scanning Electron Microscopy and measured for various tribological conditions with tactile and optical profilometry. The surface topography metrology is used to characterize the scratch profiles and to determine the volume of the displaced and removed material, and therefore the degree of wear. The originality of this paper is that it is a unique approach specifically devoted to transformer oil regeneration.