20.500.12556/RUL-109408 Razvoj in analiza sistema za merjenje trenja med rezalnim orodjem in obdelovancem pri odrezovalnih procesih Development and analysis of the system used for friction measuring between tool and workpiece in cutting processes V diplomskem delu se posvečamo eksperimentalnemu določanju koeficienta trenja med rezalnim orodjem in obdelovancem. V ta namen smo razvili nov tribometer odprtega tipa, s katerim dosegamo praktično enake kontaktne pogoje, kot nastopajo pri realnih odrezovalnih procesih. Predstavljena je zasnova tega tribometra in izvedba meritev na preizkušancih iz jekla 42CrMo4, ter titanove zlitine Ti6Al4V, v paru z neoplaščenim orodjem iz volframovega karbida WC-Co, pri različnih kontaktnih in mazalnih pogojih. Opravljena je bila primerjava rezultatov z zaprtim tribometrom, ter analiza obrabe uporabljenega rezalnega orodja za odprti tribometer. Za uporabljeno rezalno orodje se je izkazalo, da imata pri obdelavi jekla hladilna emulzija in olje zelo dober mazalni učinek, pri obdelavi titana pa je njuna učinkovitost precej omejena. Pri obeh materialih se je izkazala tudi nizka mazalna učinkovitost pri oblivanju s CO2, za katerega smo ugotovili, da praktično nima mazalnih lastnosti. Orodje je glede na material preizkušancev podvrženo različnim obrabnim mehanizmom; pri obdelavi jekla abraziji, pri obdelavi titanove zlitine pa adheziji. Iz dobljenih rezultatov smo določili aplikativno območje, znotraj katerega je smiselno uporabiti oba izmed uporabljenih tipov tribometrov, ugotovili pa smo, da je za simulacije odrezovalnih procesov odprti tribometer primernejši. Focus of this thesis is experimental determining of friction coefficient between cutting tool and workpiece. For this purpose we developed a new open type tribometer, with which we are able to achieve practically the same contact conditions, that occure in real cutting processes. The document presents the design of this tribometer and execution of measurements on 42CrMo4 steel and Ti6Al4V titanium alloy samples, which were in contact with uncoated WC-Co tungsten carbide cutting tool, at different contact and lubrication conditions. The results are compared to those obtained on the closed type tribometer and tool wear analysis for open tribometer is presented. For used cutting tool a high lubricating ability of emulsion and oil was shown on steel samples, but this ability is highly limited on titanium alloy samples. We found out, that liquid CO2 practically does not have any lubrication properties, because it showed very low lubrication ability on both materials. Two different wear mechanisms appeared on cutting tool at different sample materials; abrasive wear at machining of steel, and adhesive wear at machining of titanium alloy. Out of friction measurement results we determined an aplication range for both analysed tribometers, in which their usage is sensible, and concluded that for simulation of cutting conditions open tribometer is more suitable. koeficient trenja odprti tribometri pin-on-disc tribometri titanove zlitine primerjava obraba orodij coefficient of friction open tribometers pin-on-disc tribometers titanium alloys comparison tool wear true false false [M. Šubic] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2019-09-01 07:46:06 2019-09-01 07:46:08 2023-11-03 08:30:32 0000-00-00 00:00:00 2019 0 Ljubljana 0 XXII, [56] str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 531.43:621.9(043.2) 215518 16863003 3927.pdf 3927.pdf 1 546F1095D8F149D4DE15AB57F9017845 d159535f0b47d5d47bdc3a8f1c0a860717f8c5ea8ee107c7baaecf9d3a53de7d da4fb6ac-a1b6-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=120947 Fakulteta za strojništvo 0 0 0