Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Comparative wear behaviour of advanced tool materials in milling compacted graphite iron

Liu, Yuxinyue LU (2026) MMTM05 20261
Production and Materials Engineering
Abstract
This thesis investigates the wear behaviour of advanced cutting tools during the milling of fully pearlitic CGI 450 and ferritic-pearlitic SSF CGI 350. The hard CGI 450 primarily induced mechanical abrasive wear, whereas the highly ductile, ferrite-rich SSF CGI 350 triggered adhesive wear and built-up edge formation. EDS analysis confirmed the dynamic formation of a protective Mg-Si-O layer, which extended tool life under extreme loads. For tool life modelling, a Colding tool life model implemented in python achieved expected statistical accuracy. However, mathematical singularities emerged in the modelling results. These anomalies serve as mathematical proof of the micro-scale chemical interference, demonstrating that traditional... (More)
This thesis investigates the wear behaviour of advanced cutting tools during the milling of fully pearlitic CGI 450 and ferritic-pearlitic SSF CGI 350. The hard CGI 450 primarily induced mechanical abrasive wear, whereas the highly ductile, ferrite-rich SSF CGI 350 triggered adhesive wear and built-up edge formation. EDS analysis confirmed the dynamic formation of a protective Mg-Si-O layer, which extended tool life under extreme loads. For tool life modelling, a Colding tool life model implemented in python achieved expected statistical accuracy. However, mathematical singularities emerged in the modelling results. These anomalies serve as mathematical proof of the micro-scale chemical interference, demonstrating that traditional empirical models become physically unstable under chemical interactions. This indicates that optimal machining of advanced cast irons requires tool selection strategies that balance mechanical abrasion resistance with chemical compatibility. (Less)
Popular Abstract
Modern engines, heavy-duty vehicles, and industrial machinery require materials that are both strong and durable. One such material is Compacted Graphite Iron (CGI), which combines high mechanical strength with good thermal performance. However, these same properties make CGI difficult to machine, causing cutting tools to wear rapidly and increasing manufacturing costs.
To improve machining performance, it is important to understand how different cutting tools behave when machining different grades of CGI. This thesis investigates the wear behaviour of three cutting tool materials, including ceramic, cemented carbide, and cubic boron nitride (cBN), when machining two CGI grades with different microstructures.
Although both materials... (More)
Modern engines, heavy-duty vehicles, and industrial machinery require materials that are both strong and durable. One such material is Compacted Graphite Iron (CGI), which combines high mechanical strength with good thermal performance. However, these same properties make CGI difficult to machine, causing cutting tools to wear rapidly and increasing manufacturing costs.
To improve machining performance, it is important to understand how different cutting tools behave when machining different grades of CGI. This thesis investigates the wear behaviour of three cutting tool materials, including ceramic, cemented carbide, and cubic boron nitride (cBN), when machining two CGI grades with different microstructures.
Although both materials belong to the CGI family, their internal structures are different. CGI 450 contains a hard pearlitic matrix, while SSF CGI 350 contains a higher proportion of softer ferrite. The results show that these microstructural differences influence how cutting tools wear. The harder CGI 450 mainly caused abrasive wear, where the cutting edge is gradually worn away by hard particles in the material. In contrast, SSF CGI 350 promoted adhesive wear, where workpiece material repeatedly sticks to and detaches from the tool surface, creating a more unstable wear process.
Microscopic analysis revealed that each cutting tool material responded differently to these machining conditions. First, ceramic tools mainly suffered from brittle fracture. Second, cemented carbide exhibited stable wear accompanied by material build-up on the cutting edge. Last, cBN tools showed severe crater wear under high thermal loading. These findings demonstrate that selecting the most suitable tool depends not only on the cutting conditions but also on the microstructure of the workpiece material.
The study also discovered deposits containing magnesium, silicon, and oxygen on several worn tool surfaces. These deposits may act as a temporary protective layer between the tool and the workpiece. By modifying the contact conditions at the cutting interface, this layer may help reduce wear and extend tool life.
To better understand these effects, mathematical tool life models were developed using experimental wear data. While the models provided accurate predictions, some unusual behaviours were observed under conditions where the chemical deposits appeared. This suggests that tool wear is influenced not only by mechanical forces but also by complex chemical interactions occurring during machining.
By linking material microstructure, tool wear mechanisms, and mathematical modelling, this work contributes to a deeper understanding of CGI machining. The results can help manufacturers select more suitable cutting tools, improve machining efficiency, reduce tool consumption, and support more sustainable industrial production. (Less)
Please use this url to cite or link to this publication:
author
Liu, Yuxinyue LU
supervisor
organization
course
MMTM05 20261
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Milling, Tool life, Graphite Iron, Colding Model.
other publication id
LUTMDN/(TMMV-5391)/1-87/2026
language
English
id
9233816
date added to LUP
2026-06-11 13:00:05
date last changed
2026-06-11 13:00:05
@misc{9233816,
  abstract     = {{This thesis investigates the wear behaviour of advanced cutting tools during the milling of fully pearlitic CGI 450 and ferritic-pearlitic SSF CGI 350. The hard CGI 450 primarily induced mechanical abrasive wear, whereas the highly ductile, ferrite-rich SSF CGI 350 triggered adhesive wear and built-up edge formation. EDS analysis confirmed the dynamic formation of a protective Mg-Si-O layer, which extended tool life under extreme loads. For tool life modelling, a Colding tool life model implemented in python achieved expected statistical accuracy. However, mathematical singularities emerged in the modelling results. These anomalies serve as mathematical proof of the micro-scale chemical interference, demonstrating that traditional empirical models become physically unstable under chemical interactions. This indicates that optimal machining of advanced cast irons requires tool selection strategies that balance mechanical abrasion resistance with chemical compatibility.}},
  author       = {{Liu, Yuxinyue}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Comparative wear behaviour of advanced tool materials in milling compacted graphite iron}},
  year         = {{2026}},
}