Właściwości tribologiczne kompozytowych materiałów o osnowie stopu aluminium AK12 zbrojonych cząstkami ceramicznymi

Przedstawiono wyniki badań tribologicznych, wyznaczenie wartości współczynnika tarcia i odporności na zużycie ścierne skojarzenia ślizgowego: żeliwo-stop aluminium zbrojony cząstkami ceramicznymi Al2O3, w warunkach tarcia suchego. Badania prowadzono na stanowisku testowym tarcza-trzpień T-01M, wykorzystując materiał kompozytowy wytworzony metodą mechanicznego mieszania, zbrojony 15% udziałem objętościowym cząstek tlenku aluminium o ziarnach wielkości 15, 30, 50 um, oraz żeliwo ferrytyczno-perlitycznc z grafitem. Wyniki przeprowadzonych badań pozwalają na zaobserwowanie, iż wraz ze zmniejszeniem średnicy cząstek zbrojących spada wartość współczynnika tarcia i intensywność zużycia w analizowanym układzie tribologicznym.

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Industry wishes to develop more efficient materials for use in severe and complex conditions. Thus, not only are new materials continually developed, but also a better understanding of these materials is sought. This study was undertaken in order to evaluate basic tribological characteristics wear and friction coefficient value in dry sliding conditions. Material used for researches were disks taken from centrifugal casting composite suspension which constitution is shown in Tab. 1. Composites containing 10 % Al2O3 - particles (size 50, 30,15 um) were subjected under tests in pin-on-disc machine and counter sample for tests was pearllitic ferritic cast iron. Matrix alloy which was a reference point in examination effects was also tested. In order to evaluate friction coefficient each of the materials was examined in dry sliding conditions in five cycles at variable sliding velocity at a speed range 1:10 m/s and load 2:5 N. Wear tests were made on roadway-track equal 8000 m at load 3.5 kg and velocity 5 m/s. Tests pointed out that reinforcement which had been used raised wear resistance and its wear resistance intensity (depended on applied reinforcing particles size. The biggest was found for particles 50 um size, the smallest for particles 15 um size. Similarly in case of friction coefficient evaluating dependence between coefficient value and particle size was observed. Friction coefficient tests results are presented at Figs 2 and 3 presents wear abrasive results. On the ground of investigations that were carried out it can be concluded that there is a dependence between reinforced particles size and tribological character of the materials. Changes of the friction coefficient at speed increase that were observed need further tests in order to explain this phenomenon.