2593 KB18 KB200020242014Bílek, PavelČaplovič, L'ubomírHudáková, MáriaJurči, PeterNovák, Michalletnik:48številka:5str. 669-673COBISSID:1084074ISSN:1580-2949URN:URN:NBN:SI:doc-AOGCVX48enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijechromium nitridefriction coefficientkoeficient trenjakrom nitrid s srebromledeburitic steelsledeburitno jeklopin-on-discPVDTribology of CrAg7N coatings deposited on Vanadis 6 ledeburitic tool steel| Tribologija prevlek CrAg7N na ledeburitnem orodnem jeklu Vanadis 6|Samples made from Vanadis 6 PM ledeburitic tool steel were surface machined, ground and mirror polished. Prior to the deposition, they were heat treated to a hardness of 60 HRC. The CrAg7N coating was deposited with the magnetron-sputtering technique, using pure-Cr and Ag targets in a composite low-pressure nitrogen/argon atmosphere and at a temperature of 500 °C in the Hauzer Flexicoat 850 device. Tribological testing using a pin-on-disc apparatus was carried out at ambient and elevated temperatures: (300, 400 and 500) °C, respectively. Al2O3, 100Cr6 and CuZn balls were used as the counterparts. The wear tracks after the pin-on-disc testing were analyzed with scanning electron microscopy and a microanalysis. The experiments have shown a strong dependence of tribological parameters on the temperature. The friction coefficient of CrN-Ag against the 100Cr6 ball at ambient temperature was mi = 0.56. Tribological sliding tests of this coating system against the alumina balls indicate a decrease in the friction coefficient due to the increasing temperature. At ambient temperature mi = 0.68 and its minimum occurred at the temperature of 400 °C, mi = 0.24. This is attributed to the diffusion of Ag particles to the sliding top surface at elevated temperature. The testing against the CuZn brass ball generally gave a lower friction coefficient at ambient temperature, mi = 0.39. In contrast, the friction coefficient slightly increased with the increasing temperature and was practically constant at elevated temperatures, ranging between mi = 0.43-0.48Vzorci, izdelani iz ledeburitnega orodnega jekla Vanadis 6 PM, so bili površinsko obdelani, brušeni in zrcalno polirani. Pred nanosom so bili toplotno obdelani na trdoto 60 HRC. S tehniko magnetronskega naprševanja in z uporabo tarč iz čistega Cr in Ag je bila nanesena CrAg7N-nanoprevleka v sestavljeni nizkotlačni atmosferi iz dušika in argona pri temperaturi 500 °C v napravi Hauzer Flexicoat 850. Tribološki preizkusi s preizkuševalnikom "pin-on-disc" so bili izvršeni pri sobni temperaturi in pri povišanih temperaturah (300, 400 in 500) °C. Krogle Al2O3, 100Cr6 in CuZn so bile uporabljene kot par. Sledi obrabe po preizkusu "pin-on-disc" so bile analizirane z vrstično elektronsko mikroskopijo in z mikroanalizo. Eksperimenti so pokazali močno odvisnost triboloških parametrov od temperature. Koeficient trenja CrN-Ag proti krogli 100Cr6 pri sobni temperaturi je bil mi = 0,56. Tribološki drsni preizkusi te prevleke proti kroglam Al2O3 kažejo zmanjšanje koeficienta trenja z naraščajočo temperaturo. Pri sobni temperaturi je bil mi = 0,68, minimum pa se je pojavil pri temperaturi 400 °C, mi = 0,24. To se pripisuje difuziji delcev Ag na drsno površino pri povišanih temperaturah. Preizkušanje v paru s CuZn in medeninasto kroglo je dalo na splošno nižje koeficiente trenja pri sobni temperaturi, mi = 0,39. Nasprotno pa je koeficient trenja malo narasel pri povišanju temperature in je bil pri povišanih temperaturah praktično konstanten v območju mi = 0,43-0,48TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije