Proceedings of SerbiaTrib '13

mechanical pressure and thermal loading greatenough for initiating and maintaining an adherenceprocess.For all tested sliding speeds, the tendencycharacterizing the wear variation as a function ofload has a minimum zone around the value of 4 N.- an accentuated increase of the wear rate forloads smaller than 2.5 N, with higher values for thecomposite GB10;- for the composite GB10, the wear rate isdecreasing almost linearly when the load isincreasing and it is insignificantly decreasing whenthe sliding speed is increasing; k is smaller for thetwo composites with micro glass beads as comparedto the basic material (PBT), the lowest values beingrecorded for the composites, under the load F = 5 N;- at F = 5 N, for all the tested materials, the wearrate has a very low sensitivity to the variation of thesliding speed, the smaller values being obtained forthe composites.Thus, the wear rate diminishes when introducingglass beads in PBT. The wear is diminishing due tothe increase of the material resistance (see theresults for the composite GB10), but when themicro glass beads concentration becomes 20%, theabrasive component of the wear process increases,too.4. CONCLUSIONSAdding micro glass beads in PBT makes thefriction coefficient increase almost linearly with themicro glass beads massic concentration, with ~15%for each 10% of micro glass beads.An addition of 10% micro glass beads decreasesthe wear rate with ~20%. When the concentration ofmicro glass beads is increased, the decrease of thiswear parameter is smaller as compared to PBT, with~18%.REFERENCESFigure 5. The wear rate for PBT and the composites PBT+ micro glass beadsFor the composites PBT + micro glass beads,analysing Figure 5, the following conclusions couldbe drawn:- a zone with minimum values, for F = 5 N;[1] C.P. Fung, P.C. Kang: Multi-response optimizationin friction properties of PBT composites usingTaguchi method and principle component analysis,Journal of Materials Processing Technology, Vol.170, pp. 602-610, 2005.[2] G.S. Deshmukh, D.R. Peshwe, S.U. Pathak, J.D.Ekhe: A study on effect of mineral additions on themechanical, thermal, and structural properties ofpoly(butylene terephthalate) (PBT) composites, JPolym Res, Vol. 18, pp.1081-1090, 2011.[3] G.S. Deshmukh, D.R. Peshwe, S.U. Pathak, J.D.Ekhe: Evaluation of mechanical and thermalproperties of Poly (butylene terephthalate) (PBT)composites reinforced with wollastonite,Transactions of The Indian Institute of Metals, Vol.64, No. 1 & 2, pp. 127-132, 2011.[4] C. Georgescu, L. Deleanu: Influence of PTFEconcentration on the tribological characteristics ofPBT, in: Proceedings of the 7 th InternationalSymposium KOD 2012 Machine and IndustrialDesign in Mechanical Engineering, 24-26.05.2012,Balatonfured, Hungary, pp. 405-410.13 th International Conference on Tribology – Serbiatrib’13 117