The influence of solid lubricants on mechanical an tribological proporties of polymer composites
Zbigniew Pawelec, Jarosław Molenda, Marek Wolszczak
Quarterly No. 4, 2013 pages 260-268
DOI:
keywords: polymer composite, solid lubricants, dry friction, friction coefficient, mechanical properties
abstract The article presents the results of studies on the mechanical and tribological properties of polymer composites intended for the regeneration of sliding machine elements. Chemically cured epoxy resin Epidian 5 constituted the composites’ polymer warp. Fe powder with a define content of grains and obtained by means of reduction was used as a basic filler, whereas solid lubricants of a layered structure - graphite and molybdenum disulfide - were used as the sliding additives, and polyaramid fibres in the form of pulp - as a fibrous filler. Three series of composites with different qualitative and quantitative compositions were prepared with the addition of lubricating agents in the amount varying from 10 to 30 parts by weight in a single or combined system. The composites were crosslinked with aliphatic polyamine (triethylenetetramine), and the crosslinking process was conducted at room temperature. Once the composites were cured, their mechanical properties (i.e. resistance to compression and tear, and the module and deformation at the time of bending) were checked with the use of an Instron machine for endurance tests. The tribological characteristics of the composites in dry friction conditions were determined with a T-05 roll-block type tribotester, in which a roller with a composite layer deposited on its surface played the role of a model tribological system. A steel block, on the other hand, played the role of a counter sample. The friction and wear tests were conducted at the constant speed of slide of 0.1 m/s and changeable pressures of 0.9 and 1.5 MPa. Based on the obtained friction and wear properties and the results of investigations in which scanning electron microscopy (SEM) was applied, it was concluded that the best results are displayed when solid lubricants of a layered structure are jointly applied.