Tool wear and tool protection in metal cutting : in-process interaction between workpiece, tool, and environment
Bjerke, Axel LU
(2025)
- Abstract
- In an era where 3D printing and AI are at the forefront, turning, milling, and metal cutting might seem like niche research topics from the past. But metal cutting is all around you. If what you have lying on your desk was not machined, then the tools used to create it certainly were. Even 3D-printed or additively manufactured parts must be machined if a good surface quality is needed for an industrial application or to look shiny and nice.
Being bad at machining is very expensive—not only wasting the limited resources available to us on this planet but also most likely putting you out of business. A tool used in an industrial setting to machine metal costs at least 10 euros but can exceed 100 euros. A tool lasts about 15 minutes... (More) - In an era where 3D printing and AI are at the forefront, turning, milling, and metal cutting might seem like niche research topics from the past. But metal cutting is all around you. If what you have lying on your desk was not machined, then the tools used to create it certainly were. Even 3D-printed or additively manufactured parts must be machined if a good surface quality is needed for an industrial application or to look shiny and nice.
Being bad at machining is very expensive—not only wasting the limited resources available to us on this planet but also most likely putting you out of business. A tool used in an industrial setting to machine metal costs at least 10 euros but can exceed 100 euros. A tool lasts about 15 minutes and can be used one to four times. The tool is not even the most expensive part of the process, as the cost of the operator, machine, workpiece material, and workshop are also a big part of the cost. A tool breakage during machining is even more expensive, as it might require reworking or scrapping a part worth tens of thousands of euros.
One may think that tools are worn only through mechanical wear, but these tools are extremely hard; for example, diamond is the hardest known material. This resistance to mechanical wear makes chemical degradation play an important role. Modeling this chemical wear can save industry resources and reduce lead times in research projects. It is also a scientifically interesting topic, as chemical degradation at high temperatures and high material flow rates is a complex process that appears in many other research fields.
This thesis combines experiments, advanced microscopy, and chemical simulations to study how and why tools wear and how we can limit it. This allows us to combine the right tool material, workpiece, and process to limit tool wear. It also enables us to optimize the machining process so that a protective layer forms on the tool, further limiting wear. This discovery adds a new dimension to a research field that has been studied for over a century within a manufacturing practice spanning thousands of years.
(Less) - Abstract (Swedish)
- Om sakerna på ditt skrivbord inte har tillverkats genom skärande bearbetning, så har definitivt verktyget som användes för att tillverka dem gjort det. Skärande bearbetning har en stor men ganska dold inverkan på ditt liv. Då den enda skärande bearbetning du kanske har upplevt är att göra en ljusstake i träslöjden i grundskolan. Svarvningen och fräsningen i denna avhandling rör ej ljusstakar i trä, utan i stället svarvning av betydligt starkare legeringar av järn, nickel och titan. Verktygen i denna avhandling är inte häller av legerat stål, utan av extremt slitstarka och hårda keramiska material.
Ett verktyg i industrin håller cirka en kvart, och kan användas en till fyra gånger och kostar från 100 kr till flera tusen kr, och då... (More) - Om sakerna på ditt skrivbord inte har tillverkats genom skärande bearbetning, så har definitivt verktyget som användes för att tillverka dem gjort det. Skärande bearbetning har en stor men ganska dold inverkan på ditt liv. Då den enda skärande bearbetning du kanske har upplevt är att göra en ljusstake i träslöjden i grundskolan. Svarvningen och fräsningen i denna avhandling rör ej ljusstakar i trä, utan i stället svarvning av betydligt starkare legeringar av järn, nickel och titan. Verktygen i denna avhandling är inte häller av legerat stål, utan av extremt slitstarka och hårda keramiska material.
Ett verktyg i industrin håller cirka en kvart, och kan användas en till fyra gånger och kostar från 100 kr till flera tusen kr, och då ska man ha i åtanke att oftast är det inte verktyget som är det dyra, utan även maskinen, materialet man bearbetar, operatören och lokalen är en stor del av kostanden. Att behöva kassera eller ombearbeta om en nästan färdig produkt på grund av ett verktyg som har fallerat kan bli en ännu större kostnad speciellt vid tillverkning av turbindelar i legeringar av nickel och titan (hundratusentals kronor).
Man kan tro att verktygsmaterialen slits enbart mekaniskt, men så är inte fallet, verktygsmaterialen är mycket resistenta mot denna typ av förslitning. Diamant är till exempel det hårdaste materialet människan känner till. Förslitning på grund av kemisk nedbrytning spelar därför en betydande roll. Att välja rätt material är då extremt viktigt, diamant slits till exempel ner efter ett par sekunder om man svarvar rostfritt stål. Att kunna modellera spar både dyra resurser ute in industrin och spar ledtid vid utveckling av nya verktygsmaterial. Det är också vetenskapligt intressant att studera diffusion, kemisk nedbrytning och oxidation vid höga temperaturer och vid höga materialflöden eftersom det är en komplex process som även dyker upp i andra forskningsområden.
Denna avhandling kombinerar experiment, avancerad mikroskopi och kemiska simuleringar av svarvning för att förstå hur och varför skärverktyg slits, och hur vi kan få dem att slitas mindre. Forskningsresultaten hjälper oss att kombinera rätt verktygsmaterial med rätt arbetsmaterial mer effektivt. Vi kan vidare använda dessa simuleringar för att kombinera material och process så att skyddsskikt bildas på verktyget under svarvningen. Att kunna göra detta är en ny upptäckt, i detta hundraåriga forskningsfält av en tusenårig tillverkningsmetod!
(Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/80cac84c-35bb-41ad-a212-43aa0fcf0c84
- author
- Bjerke, Axel
LU
- supervisor
- opponent
-
- Assoc. Prof. de Oro Calderon, Raquel, TU Wien, Austria.
- organization
-
- Sentio: Integrated Sensors and Adaptive Technology for Sustainable Products and Manufacturing
- SEM-lab
- LU Profile Area: Light and Materials
- LTH Profile Area: Nanoscience and Semiconductor Technology
- SPI: Sustainable Production Initiative
- NanoLund: Centre for Nanoscience
- Production and Materials Engineering
- alternative title
- Kemiska och termodynamiska interaktioner mellan verktyg och arbetsmaterial
- publishing date
- 2025-05-28
- type
- Thesis
- publication status
- published
- subject
- keywords
- machinability, thermodynamic modeling of tool wear, electron microscopy of cutting tools, tool protection layers (TPL)
- pages
- 100 pages
- publisher
- Department of Industrial and Mechanical Sciences
- defense location
- Lecture Hall M:B, building M, Ole Römers väg 1F, Faculty of Engineering LTH, Lund University, Lund.
- defense date
- 2025-05-28 09:00:00
- ISBN
- 978-91-8104-491-1
- 978-91-8104-492-8
- language
- English
- LU publication?
- yes
- id
- 80cac84c-35bb-41ad-a212-43aa0fcf0c84
- date added to LUP
- 2025-04-24 15:51:25
- date last changed
- 2025-05-01 03:16:55
@phdthesis{80cac84c-35bb-41ad-a212-43aa0fcf0c84,
abstract = {{In an era where 3D printing and AI are at the forefront, turning, milling, and metal cutting might seem like niche research topics from the past. But metal cutting is all around you. If what you have lying on your desk was not machined, then the tools used to create it certainly were. Even 3D-printed or additively manufactured parts must be machined if a good surface quality is needed for an industrial application or to look shiny and nice.<br/><br/>Being bad at machining is very expensive—not only wasting the limited resources available to us on this planet but also most likely putting you out of business. A tool used in an industrial setting to machine metal costs at least 10 euros but can exceed 100 euros. A tool lasts about 15 minutes and can be used one to four times. The tool is not even the most expensive part of the process, as the cost of the operator, machine, workpiece material, and workshop are also a big part of the cost. A tool breakage during machining is even more expensive, as it might require reworking or scrapping a part worth tens of thousands of euros.<br/><br/>One may think that tools are worn only through mechanical wear, but these tools are extremely hard; for example, diamond is the hardest known material. This resistance to mechanical wear makes chemical degradation play an important role. Modeling this chemical wear can save industry resources and reduce lead times in research projects. It is also a scientifically interesting topic, as chemical degradation at high temperatures and high material flow rates is a complex process that appears in many other research fields.<br/><br/>This thesis combines experiments, advanced microscopy, and chemical simulations to study how and why tools wear and how we can limit it. This allows us to combine the right tool material, workpiece, and process to limit tool wear. It also enables us to optimize the machining process so that a protective layer forms on the tool, further limiting wear. This discovery adds a new dimension to a research field that has been studied for over a century within a manufacturing practice spanning thousands of years.<br/>}},
author = {{Bjerke, Axel}},
isbn = {{978-91-8104-491-1}},
keywords = {{machinability; thermodynamic modeling of tool wear; electron microscopy of cutting tools; tool protection layers (TPL)}},
language = {{eng}},
month = {{05}},
publisher = {{Department of Industrial and Mechanical Sciences}},
school = {{Lund University}},
title = {{Tool wear and tool protection in metal cutting : in-process interaction between workpiece, tool, and environment}},
url = {{https://lup.lub.lu.se/search/files/217838265/Axel_Bjerke_-_HELA.pdf}},
year = {{2025}},
}