Influence of Varying Concentrations of Epoxy, Rice Husk, Al2O3, and Fe2O3 on the Properties of Brake Friction Materials Prepared Using Hand Layup Method

Our plain-English summary of Influence of Varying Concentrations of Epoxy, Rice Husk, Al2O3, and Fe2O3 on the Properties of Brake Friction Materials Prepared Using Hand Layup Method, by A.P. Irawan, D.F. Fitriyana, J.P. Siregar, et al (Polymers, 2023).

The study

• Authors: A.P. Irawan, D.F. Fitriyana, J.P. Siregar, T. Cionita, P.T. Anggarina, D.W. Utama, T. Rihayat, R. Rusiyanto, S. Dimyati, M.B. Aripin, R. Ismail, A.P. Bayuseno, G.D. Baskara, M. Khafidh, F.P. Putera, R. Yotenka
• Journal: Polymers
• Published: 2023;15(12)
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Brake friction materials (BFMs) have a critical role in ensuring the safety as well as the reliability of automotive braking systems. However, traditional BFMs, typically made from asbestos, are associated with environmental and health concerns. Therefore, this results in a growing interest in developing alternative BFMs that are eco-friendly, sustainable, and cost-effective. This study investigates the effect of varying concentrations of epoxy, rice husk, alumina (Al2O3), and iron oxide (Fe2O3) on the mechanical and thermal properties of BFMs prepared using the hand layup method. In this study, the rice husk, Al2O3, and Fe2O3 were filtered through a 200-mesh sieve. Note that the BFMs were fabricated using different combinations and concentrations of the materials. Their mechanical properties, such as density, hardness, flexural strength, wear resistance, and thermal properties, were investigated. The results suggest that the concentrations of the ingredients significantly influence the mechanical and thermal properties of the BFMs. A specimen made from epoxy, rice husk, Al2O3, and Fe2O3 with concentrations of 50 wt.%, 20 wt.%, 15 wt.%, and 15 wt.%, respectively, produced the best properties for BFMs. On the other hand, the density, hardness, flexural strength, flexural modulus, and wear rate values of this specimen were 1.23 g/cm3, 81.2 Vickers (HV), 57.24 MPa, 4.08 GPa, and 8.665 × 10-7 mm2/kg. In addition, this specimen had better thermal properties than the other specimens. These findings provide valuable insights into developing eco-friendly and sustainable BFMs with suitable performance for automotive applications.

In plain English

This was a laboratory materials study. It did not examine asbestos exposure or any health outcome. Asbestos appears only as background: it is the traditional brake material that alternatives like these are meant to replace. The authors made six test brake friction materials by hand, mixing epoxy resin with different amounts of rice husk powder, alumina (Al2O3) and iron oxide (Fe2O3). Specimen BP_1 was pure epoxy. BP_6 was 50% epoxy, 20% rice husk and 15% each of alumina and iron oxide by weight. BP_6 had the highest density (1.23 g/cm3), hardness (81.2 HV) and flexural strength (57.27 MPa), and BP_3 had the lowest. Wear and heat tests were run only on BP_1 and BP_6. BP_6 wore at 8.67 × 10−7 mm2/kg, compared with 9.1 × 10−7 mm2/kg for BP_1. That was more wear than figures for commercial products reported in an earlier study. Heated to 700 degrees C, BP_6 left more residue than BP_1 (50.59% versus 16.81%). The authors concluded that alumina and iron oxide at 15 wt.% gave good bonding and higher density.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory materials experiment: brake friction material specimens of differing composition were made by hand layup and tested for density, flexural properties, hardness, wear, thermal behaviour and microscopic structure. No human or animal subjects.
• Who was studied: Six brake friction material specimens (BP_1 to BP_6), from pure epoxy (BP_1) to 50 wt.% epoxy with rice husk, Al2O3 and Fe2O3 in varying proportions. The rice husk came from rice processing in Gunungpati, Semarang City, Indonesia.
• Exposure: No asbestos was studied. The materials tested were epoxy resin with hardener, rice husk powder, alumina (Al2O3) and iron oxide (Fe2O3), each sieved to 200 mesh. Asbestos is mentioned only as the traditional material being replaced.
• Main results:
  • BP_6 (50 wt.% epoxy, 20 wt.% rice husk, 15 wt.% Al2O3, 15 wt.% Fe2O3) had the highest density, 1.23 g/cm3.
  • BP_3 had the lowest density, 1.03 g/cm3. Pure epoxy (BP_1) had a density of 1.21 g/cm3.
  • Flexural strength and flexural modulus were 57.27 MPa and 4.08 GPa for BP_6 (the highest), 20.77 MPa and 1.15 GPa for BP_3 (the lowest), and 34.68 MPa and 1.26 GPa for BP_1.
  • Hardness was 81.2 HV for BP_6 (the highest), 38.3 HV for BP_3 (the lowest) and 58.7 HV for pure epoxy (BP_1).
  • Wear, SEM and thermal (TGA/DSC) tests were done only on BP_1 and BP_6.
  • Specific wear rates were 9.1 × 10−7 mm2/kg for BP_1 and 8.67 × 10−7 mm2/kg for BP_6. The authors noted that BP_6's rate was greater than the rates for commercial products (6.5 × 10−7 and 5.9 × 10−7 mm2/kg) reported in an earlier study.
  • Between 250 and 550 degrees C, weight loss was 43.37% for BP_6 and 78.7% for BP_1. The residue at 700 degrees C was 50.59% for BP_6 and 16.81% for BP_1.
• The authors' conclusion: The authors concluded that Al2O3 and Fe2O3 at 15 wt.% gave effective interfacial adhesion and higher density. They also concluded that concentrations above 15 wt.% made homogeneous mixing difficult, causing agglomerates and poorer properties.

Topics

Medical terms in this study, explained in our Lexicon: Hardness (Mohs Scale).

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