Surface wear and structure after collaboration in dry sliding condictions in MMCs AK12 and ceramic particles Al2O3
Jakub Wieczorek, Józef Śleziona, Jerzy Myalski, Anna Dolata - Grosz, Maciej Dyzia Politechnika Śląska, Wydział Inżynierii Materiałowej Metalurgii i Transportu, ul. Krasińskiego 8, 40-019 Katowice
Annals 3 No. 6, 2003 pages 131-135
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abstract Aluminium-based metal matrix composites are well-known for their high specific strength, stiffness and hardness. They are gaining further importance as their potential for wear resistance becomes established. In general, for sliding against metal and abrasives, many studies have reported that composites exhibit better wear resistance than the unreinforced alloys. Aluminium-based metal-matrix composites have found application in the manufacture of various automotive engine components such as cylinder blocks, pistons and piston insert rings where adhesive wear (or dry sliding wear) is a predominant process. Materials possessing high wear resistance (under dry sliding conditions) are associated with a stable tribolayer on the wearing surface and the formation of fine equiaxed wear debris. For adhesive wear, the influence of applied load, sliding speed, wearing surface hardness, reinforcement fracture toughness and morphology are critical parameters in relation to the wear regime encountered by the material. Article presents the results of the researches on the surface of composites MMCs reinforced Al2O3 particles after mating in technically dry friction conditions are presented. Investigations were made with the use of Taylor-Hobson profilograph. Tested materials were matrix alloy composites AK12 reinforced Al2O3 particles (10, 25.50 μm) (Tab. 1), after collaboration with cast iron. For all samples sliding distance was 5000 m, load 35 N and sliding velocity 0.5 m/s. Abrasion was carried out with the use of tribological tester T-01 pin-on-disc. On the bowies of the investigations it can be stated that: In MMCs reinforced different diameter particles there is proportional dependence between geometry surface parameters and reinforced particles diameter. Friction coefficient value and wear resistance in investigated MMCs layers depend on particle size used as reinforcement. Together with reduction of particles diameter friction coefficient and wear value decrease. In tribological systems working in dry sliding conditions there is a possibility that tribological properties controlled by particle size change surface geometry and particle size decide wear character. Key words: composites Al-ceramic particles, wear, dry sliding, structure