Investigation of the use of metallic slags as filler in automotive friction material

In this research, the use of metallic slags as fillers in the production of automotive brake lining was investigated. In the first stage, content optimization was performed. In the content optimization stage, at different mass rates; phenolic resin, bronze powder, brass shavings, glass fiber, steel wool, barite, graphite and alumina were used. The average coefficient of friction, specific wear rate, friction stability, density, hardness and some physical properties of 46 ingredients prepared in different proportions were determined. In the second stage, the average coefficient of friction, specific wear rate and friction stability values were modeled using the 46 samples produced. Multigene genetic programming, one of the genetic programming methods, was used for modeling. 39 of the 46 test samples were used for training and the remaining 7 were used for validation. According to all model data results, the R2 values of average friction coefficient, specific wear rate and friction stability were obtained as 95%, 93% and 86% respectively. In the third stage, optimization of the production parameters was carried out. Cold pressing and pressure, hot pressing time-pressure and temperature, curing temperature and time were optimized. According to the production optimization, 3 min for pre-forming time, 12 MPa for pre-forming pressure; 15 min for hot pressing time, 12 MPa for hot pressing pressure, and 150°C for hot pressing temperature; and a curing time of 8 h and curing temperature of 150 °C has been determined. In the last stage, the use of blast furnace, copper and aluminum slag materials as filler materials in brake linings with optimized content and production parameters was investigated. While 40% barite was used in the sample, this ratio was reduced by 10% for each slag material and the proportion of slag material was increased by 10%. According to the results obtained, it was suggested that it is appropriate to use blast furnace slag up to 10%, copper slag up to 30% and aluminum slag up to 20% in the brake lining composition.