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A PIN-ON-DISC STUDY ON THE FRICTION, WEAR AND AIRBORNE PARTICLE EMISSION FROM RECYCLED BRAKE PAD MATERIAL

Lyu, Yezhe LU orcid ; Leonardi, Mara ; Ma, Jijie ; Wahlström, Jens LU orcid ; Gialanella, Stefano and Olofsson, Ulf (2019) Eurobrake 2019
Abstract
A brake pad is usually replaced before it is totally worn off. Some of these pads are re-melted as scarps in electrical arc furnace process, arising some concerns for the potential emissions due to the combustion of the organic component of the friction material and pad underlayer. To a lower extent, the other exhaust pads are taken to the scrap yard as waste. The concept of this study is to recycle the replaced brake pads, by ball milling the residual friction material into powders followed by hot compressing into new brake pads. A pin-on-disc tribometer designed for particle emission measurement is used to test the virgin and recycled friction material against a commercial cast iron brake rotor material in a controlled environment, to... (More)
A brake pad is usually replaced before it is totally worn off. Some of these pads are re-melted as scarps in electrical arc furnace process, arising some concerns for the potential emissions due to the combustion of the organic component of the friction material and pad underlayer. To a lower extent, the other exhaust pads are taken to the scrap yard as waste. The concept of this study is to recycle the replaced brake pads, by ball milling the residual friction material into powders followed by hot compressing into new brake pads. A pin-on-disc tribometer designed for particle emission measurement is used to test the virgin and recycled friction material against a commercial cast iron brake rotor material in a controlled environment, to assess their tribological properties. Three factors (pressure, sliding speed and material) form a 23 full factorial experiment. Two pressure levels (1.2 MPa and 0.3 MPa), two sliding speed levels (2 m/s and 1m/s) are tested on two materials (virgin and recycled). The contact conditions correspond to typical city traffic conditions. Coefficient of friction (CoF), total wear of the pin and disc sample, particle generation rate are the response variables from the tests. The results show that the recycled brake pad averages a greater CoF and lower total wear than the virgin brake pad under the current test conditions. This is likely due to the more homogenous microstructure distribution of the recycled pins. Under tougher braking condition (1.2 MPa + 2 m/s) and normal braking condition (1.2 MPa + 1 m/s and 0.3 MPa + 2 m/s), the recycled brake pad demonstrates lower particle generation rate than virgin brake pad. When the pressure and sliding speed are both low (0.3 MPa + 1 m/s), the recycled brake pad has greater particle generation rate than virgin brake pad. In this regard, the results confirm the feasibility of the proposed recycling procedure. However, for a full assessment and validation of the process, two main further actions are required. One is to compare the current tribological results with those obtained with pins extracted from real pads, considering also the possible effect of pad scorching, will be conducted. The other is to conduct a complete life cycle analysis, providing reliable indications as concerns the scaling up of the recycling approach to industrial level. (Less)
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author
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publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
Eurobrake 2019
publisher
FISITA
conference name
Eurobrake 2019
conference location
Dresden, Germany
conference dates
2019-05-21 - 2019-05-23
ISBN
978-0-9572076-3-9
language
English
LU publication?
no
id
da641dfe-674a-44fd-a575-07b8a90a1d6e
alternative location
https://go.fisita.com/store/papers/EuroBrake2019/EB2019-FBR-028?search=53616c7465645f5f5ba3c3de9a43ce2fd7d7edc97c00d54cc6e65d028eb73f7072258eb59e3a7b2f945375cd17884175a8fedc36df88f688b996dda4a1436933617ed371a55d0290a5e3adc5fa57eb04b4afc3b14b6e59e500bfa3db017dd329
date added to LUP
2021-10-26 10:50:28
date last changed
2021-12-10 13:11:43
@inproceedings{da641dfe-674a-44fd-a575-07b8a90a1d6e,
  abstract     = {{A brake pad is usually replaced before it is totally worn off. Some of these pads are re-melted as scarps in electrical arc furnace process, arising some concerns for the potential emissions due to the combustion of the organic component of the friction material and pad underlayer. To a lower extent, the other exhaust pads are taken to the scrap yard as waste. The concept of this study is to recycle the replaced brake pads, by ball milling the residual friction material into powders followed by hot compressing into new brake pads. A pin-on-disc tribometer designed for particle emission measurement is used to test the virgin and recycled friction material against a commercial cast iron brake rotor material in a controlled environment, to assess their tribological properties. Three factors (pressure, sliding speed and material) form a 23 full factorial experiment. Two pressure levels (1.2 MPa and 0.3 MPa), two sliding speed levels (2 m/s and 1m/s) are tested on two materials (virgin and recycled). The contact conditions correspond to typical city traffic conditions. Coefficient of friction (CoF), total wear of the pin and disc sample, particle generation rate are the response variables from the tests. The results show that the recycled brake pad averages a greater CoF and lower total wear than the virgin brake pad under the current test conditions. This is likely due to the more homogenous microstructure distribution of the recycled pins. Under tougher braking condition (1.2 MPa + 2 m/s) and normal braking condition (1.2 MPa + 1 m/s and 0.3 MPa + 2 m/s), the recycled brake pad demonstrates lower particle generation rate than virgin brake pad. When the pressure and sliding speed are both low (0.3 MPa + 1 m/s), the recycled brake pad has greater particle generation rate than virgin brake pad. In this regard, the results confirm the feasibility of the proposed recycling procedure. However, for a full assessment and validation of the process, two main further actions are required. One is to compare the current tribological results with those obtained with pins extracted from real pads, considering also the possible effect of pad scorching, will be conducted. The other is to conduct a complete life cycle analysis, providing reliable indications as concerns the scaling up of the recycling approach to industrial level.}},
  author       = {{Lyu, Yezhe and Leonardi, Mara and Ma, Jijie and Wahlström, Jens and Gialanella, Stefano and Olofsson, Ulf}},
  booktitle    = {{Eurobrake 2019}},
  isbn         = {{978-0-9572076-3-9}},
  language     = {{eng}},
  publisher    = {{FISITA}},
  title        = {{A PIN-ON-DISC STUDY ON THE FRICTION, WEAR AND AIRBORNE PARTICLE EMISSION FROM RECYCLED BRAKE PAD MATERIAL}},
  url          = {{https://go.fisita.com/store/papers/EuroBrake2019/EB2019-FBR-028?search=53616c7465645f5f5ba3c3de9a43ce2fd7d7edc97c00d54cc6e65d028eb73f7072258eb59e3a7b2f945375cd17884175a8fedc36df88f688b996dda4a1436933617ed371a55d0290a5e3adc5fa57eb04b4afc3b14b6e59e500bfa3db017dd329}},
  year         = {{2019}},
}