doktorsko delo
Aljaž Ščetinec (Author), Damjan Klobčar (Mentor), Drago Bračun (Co-mentor)

Abstract

Predložena disertacija obravnava razvoj procesa oblikovnega obločnega navarjanja (OON) z žico in poobdelavo za doseganje skoraj-končne oblike in želenih materialnih lastnosti materiala. Prvi naslovljeni izziv so variacije v procesnih parametrih OON. Te imajo negativen vpliv na končno obliko izdelka. Naslednji izziv pri OON je visok linearni vnos energije ter ciklično segrevanje in ohlajanje materiala med gradnjo. Zato je za doseganje ustreznih materialnih lastnosti po navarjanju potrebna toplotna obdelava, ki v primeru jekla 15-5 PH sestoji iz topilnega žarjenja in staranja. Parametri toplotne obdelave za 15-5 PH so znani zgolj za konvencionalno izdelan material. Poleg tega osnovne mehanske lastnosti OON 15-5 PH še niso znane. V okviru doktorske naloge smo razvili napreden sistem za OON, ki omogoča doseganje skoraj-končne oblike izdelkov kompleksne geometrije. To smo dosegli s spremljanjem višine sloja prek električnih parametrov obloka in med-procesno rekonstrukcijo 3D-poti navarjanja. Delovanje sistema smo preverili z navarjanjem tankostenskega lupinastega izdelka. Dodatno smo z ustreznimi porušnimi in neporušnimi metodami razvili in optimirali temperature in čase topilnega žarjenja ter staranja. Topilno žarjenje je treba izvajati pri višjih temperaturah in dlje časa od konvencionalno izdelanega 15-5 PH. Rezultat je homogena trdna raztopina, ki s staranjem omogoča doseganje materialnih lastnosti, ki so primerljive z že znanim lastnostim konvencionalno izdelanega materiala 15-5 PH.

Keywords

disertacije;oblikovno obločno navarjanje z žico;sprotno merjenje višine sloja;vodenje pomika Z osi;medprocesna rekonstrukcija poti orodja;martenzitno nerjavno jeklo za izločevalno utrjevanje;15-5PH;topilno žarjenje;staranje;

Data

Language: Slovenian
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UL FS - Faculty of Mechanical Engineering
Publisher: [A. Ščetinec]
UDC: 621.791.75:669.14:620.17(043.3)
COBISS: 169078787 Link will open in a new window
Views: 41
Downloads: 9
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Other data

Secondary language: English
Secondary title: Wire arc additive manufacturing and post-processing for achieving near net shape deposit with selected material properties
Secondary abstract: The proposed PhD thesis aims to develop wire arc additive manufacturing (WAAM) and post-processing for achieving near net shape deposit with selected material properties. The first challenge addressed in this research is the inherent variations in the WAAM process parameters which have a negative impact on the final shape of the product. The next addressed challenge is the high linear heat input and heating/cooling cycles of the material during the deposition. Therefore, to achieve the desired material properties in the case of 15-5 PH steel, heat treatment (solution annealing and aging) is required. However, heat treatment parameters are only known for conventionally produced 15-5 PH. Furthermore, even the basic mechanical properties of WAAM 15-5 PH have not yet been studied. To address these challenges, an advanced WAAM system has been developed. The system enables near-net shape deposition of complex geometry parts by online monitoring of the layer height through electric parameters of the arc and in-process path replanning. The system’s operation was verified by deposition of thin-walled shell part. Additionally, appropriate destructive and non-destructive methods were used to develop and optimize the solution annealing and aging temperatures and times. The solution annealing process needs to be carried out for a longer time and at a higher temperature than conventionally produced 15-5 PH. The result is a homogenous solid solution that enables aging with comparable mechanical properties to conventionally produced 15-5 PH.
Secondary keywords: dissertations;wire arc additive manufacturing;online layer height measurement;Z increment control;in-process path replanning;precipitation hardening martensitic stainless steel;15-5 PH, solution annealing, aging;
Type (COBISS): Doctoral dissertation
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za strojništvo
Pages: XXIV, [127] str.
ID: 20010356