Ispitivanje trošenja spiralnih svrdla prevučenih prevlakom PACVD TiN

undergraduate thesis

• Title (english): Wear testing of PACVD TiN coated drill bits
• Author: Ivan Huđ
• Mentor: Darko Landek (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Kada se ispituje trošenje svrdla postoji niz modela trošenja koji se uglavnom primjenjuju kod
obrade metalnih materijala. Prilikom rada svrdla su izložena visokim mehaničkim i toplinskim
naprezanjima te se prevlačenjem svrdla povećava otpornost trošenju. Najčešće prevlake koje se
koriste kod prevlačenja svrdla su PACVD TiN i PVD TiN.
U teorijskom dijelu ovog rada opisani su brzorezni čelici od kojih izrađuju svrdla, njihova
mikrostruktura, toplinska obrada te postupci prevlačenja iz parne faze. Opisana je geometrija
oštrice spiralnog svrdla i sile rezanja kod bušenja te procesi trošenja svrdla.
U eksperimentalnom dijelu provedeno je prevlačenje svrdla od brzoreznog čelika prevlakom
PACVD TiN. Na prevučenim svrdlima ispitana je mikrostruktura, tvrdoća, debljina i
prionjivost prevlake.
Provedeno je niz bušenja u aluminijevom disku s neprevučenim svrdlom, svrdlom s prevlakom
PACVD TiN i komercijalno dobavljivim svrdlom s prevlakom PVD TiN. Tijekom bušenja u
ukupnom trajanju od 120 s, svjetlosnom mikroskopijom dokumentirano je trošenje svrdla
svakih 30 s. Termografskom kamerom je mjerena temperatura oštrice svrdla i aluminijskog
diska. Obje vrste prevučenih svrdla pokazala su manje trošenje oštrice od neprevučenih svrdla.
Svrdlo s PACVD TiN prevlakom više se ugrijavalo pri bušenju u odnosu na neprevučeno i
svrdlo s PVD TiN prevlakom.

Abstract (english)

When testing the wear of drill bits, there is a number of wear models that are mainly used in
the processing of metal materials. During operation, the drill bits are exposed to high
mechanical and thermal stresses, and by coating the drill bit, the resistance to wear increases.
The most common coatings used when coating drills are PACVD TiN and PVD TiN.
In the theoretical part of this paper, the high-speed steel which the drills are made of, their
microstructure, heat treatment and vapor phase coating procedures are described. The geometry
of the spiral drill blade and the cutting force during drilling are described, as well as the wear
processes of the drill bit.
In the experimental part, high-speed steel drills were coated with PACVD TiN coating. The
microstructure, hardness, thickness and adhesion of the coating were tested on the coated drill
bits.
A series of drills were performed on an aluminum disc with an uncoated drill bit, a PACVD
TiN coated drill bit, and a commercially available PVD TiN coated drill bit. During drilling for
a total duration of 120 s, the wear of the drill bit was documented with light microscopy every
30 s. The temperature of the drill blade and the aluminum disc was measured with a
thermographic camera. Both types of coated drills showed less blade wear than uncoated drills.
The drill bit with PACVD TiN coating heated up more when drilling compared to the uncoated
drill bit and drill bit with PVD TiN coating.

• Keywords: svrdlo; prevlaka PACVD TiN; prevlaka PVD TiN; trošenje svrdla
• Keywords (english): drill bit; PACVD TiN coating; PVD TiN coating; drill bit wear
• Language: croatian
• URN:NBN: urn:nbn:hr:235:328215
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-01 15:11:48