Popis deformacije odrezkov pri struženju z visokotlačnim dovajanjem hladilno-mazalne tekočine v rezalno cono

Štepec, Jakob (author), Pušavec, Franci (mentor)

V magistrskem delu smo zasnovali analitični mehanski model lomljenja odrezkov s katerim je na podlagi dobljenih rezultatov mogoče napovedovati stopnjo mehanske deformacije oziroma lomljenje odrezkov pri pulzirajočem dovajanju hladilno-mazalne tekočine (HMT) v rezalno cono pri postopku struženja. Pri finih obdelavah, posebej pri struženju težko obdelovalnih materialov med katere spada tudi Ti6Al4V zlitina, pogosto prihaja do problemov z odrezki. Kot ena izmed rešitev te težave se ponuja pulzirajoče dovajanje HMT, kjer s povišanim tlakom dodatno deformiramo odrezek do te mere, da se le ta zlomi. Količino deformacije odrezka, kot posledico delovanja curka HMT, smo želeli popisati z razvojem modela. Za namen preverjanja ustreznosti zasnovanega analitičnega modela so bili v eksperimentalnem delu izvedeni eksperimenti. Analiziran je bil vpliv procesnih parametrov struženja in parametrov visokotlačnega dovajanja HMT na lom odrezkov. Za ugotovitev kako curek deluje na odrezek, smo z eksperimentom popisali obliko prečnega preseka curka in porazdelitev tlaka curka HMT, ki zadane odrezek in rezalno orodje. Ugotovljeno je bilo, da imajo procesni parametri struženja (podajanje, globina rezanja) in parametri pulzirajočega visokotlačnega dovajanja HMT v rezalno cono velik vpliv na proces lomljenja odrezkov. Z upoštevanjem ugotovljenih tlačnih izgub HMT pri analizi tlaka, ki deluje na odrezek smo ugotovili, da je zasnovani analitični mehanski model lomljenja odrezkov primeren za napovedovanje potrebnega tlaka HMT za kritično deformacijo oziroma lom odrezka.

• Language: Slovenian
• Keywords: struženje, odrezki, visokotlačno odrezavanje, Ti6Al4V, analitični mehanski model lomljenja odrezkov
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [J. Štepec]
• Year: 2021
• Number of pages: XXII, 93 str.
• PID: 20.500.12556/RUL-133032
• UDC: 621.941:669.2:539.37(043.2)
• COBISS.SI-ID: 84926979
• Publication date in RUL: 08.11.2021

ŠTEPEC, Jakob, 2021, Popis deformacije odrezkov pri struženju z visokotlačnim dovajanjem hladilno-mazalne tekočine v rezalno cono [online]. Master’s thesis. Ljubljana : J. Štepec. [Accessed 25 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=133032

Secondary language

• Language: English
• Title: Survey of chip deformation during turning with high-pressure supply of coolant to the cutting zone

Abstract

In the master's thesis, we designed an analytical mechanical model of chip breaking with which, based on the obtained results, it is possible to predict the degree of mechanical deformation or chip breaking during pulsating supply of coolant to the cutting zone during turning. In fine machining, especially in the turning of difficult-to-machine materials, including the Ti6Al4V alloy, chip problems often occur. As one of the solutions to this problem, a pulsating supply of coolant is offered, where with increased pressure we additionally deform the chip to such an extent that it breaks. The amount of chip deformation as a consequence of coolant jet action was to be described by model development. In order to verify the adequacy of the designed analytical model, experiments were performed in the experimental part. The influence of turning process parameters and highpressure coolant parameters on chip fracture was analyzed. To determine how the jet acts on the chip, we experimentally described the shape of the cross section of the jet and the pressure distribution of the coolant jet that hits the chip and the cutting tool. It was found that the process parameters of turning (feed, depth of cut) and the parameters of pulsating high-pressure supply of coolant to the cutting zone have a great influence on the process of chip breaking. Taking into account the determined pressure losses of coolant in the analysis of the pressure acting on the chip, we found that the designed analytical mechanical model of chip fracture is suitable for predicting the required coolant pressure for critical deformation or fracture of the chip.

• Keywords: turning, chip formation, high pressure turning, Ti6Al4V, analitical chip breaking model