Banca de QUALIFICAÇÃO: MICAEL GONÇALVES MULLER

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : MICAEL GONÇALVES MULLER
DATA : 03/10/2022
HORA: 18:30
LOCAL: Campus Feliz (defesa online)
TÍTULO:

Analysis of the influence of different panox fiber contents on the mechanical and physical properties and the reduction of sparks in friction material applied on automotive brakes

PALAVRAS-CHAVES:

Oxidized Polyacrylonitrile, Brake Pad, Spark.

PÁGINAS: 19
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Materiais Conjugados Não-Metálicos
RESUMO:

Currently, several researches related to binding materials, friction modifiers and mechanical reinforcements are being reported, and also new studies related to fibers and functional loads are being explored. However, optimizing the frictional properties is a complex task given the high performance required and the reduced wear levels and low aggressiveness of the brake disc. These complexities increase when factors such as heating of the brake system and generation of sparks during the braking process need to be minimized due to the severe applications in which the brake system is subjected. In this field, studies have been conducted in order to identify these factors, considering materials that can attenuate or eliminate the generation of sparks and, at times, the ignition of materials. In this context, the aim of this work is to develop a new composition of friction material for automotive brakes, with tribological and physical properties suitable for reducing sparks. For this, the oxidized polyacrylonitrile fiber (PANOX) was added in combination with the materials of the base formulation of the brake system, with equivalent percentage variations of 1:1 (sample S1), 1:2 (sample S2) and 1:4 (sample S3) in volume when compared to the aramid fiber originally used. The raw materials were mixed, after which the brake pads were pressed at an average temperature of 140 to 160°C, and an average pressure of 180 to 200 bar. After this step, the samples were heat-treated for 8 h at temperatures between 200 and 230°C. The test procedure FMVSS 121D on an air brake system with speed, pressure and temperature variations was carried out. The test pressure was varied from 1.5 to 9 bar, obtaining torque responses between 2 and 19 kNm, and evaluated at temperatures of 100°C and 300°C. The spark analysis generated in the applications was also performed. The characterization of the physical properties was carried out through tests of internal shear force, compressibility and thermal transmissibility. When analyzing the torque results as a function of pressure, at both temperatures tested, the results were similar between the base sample and sample S3. It was possible to verify that the spark generation in the S3 sample was equivalent to the base material, different from the results presented in the S1 sample, showing a tendency of reduction of the spark generation with the addition of the PANOX fiber. Furthermore, samples containing PANOX fiber presented higher values for the internal shear force, and the compressibility values increased for the S3 sample. Thus, from this preliminary study, it can be seen that, for S3 sample, the same percentage of spark was generated, while there was an improvement in the physical properties, in relation to the base material.

MEMBROS DA BANCA:
Presidente - 2383615 - DAIANE ROMANZINI
Interno - 1580090 - ANDRE ZIMMER
Interno - 1997577 - ALEXANDRE LUIS GASPARIN