Modeling of Compaction Processes of Friction Material Mixes

Composite materials manufacturing

“…It is important to select the optimum compression pressure for each new mix. According to [31], the friction material has a higher density on the piston side, and the density decreases towards the backplate side owing to frictional losses at the wall during compression.…”

“…The compression process is interrupted by breathing cycles, to expel the gases produced in the cavity. Finally, the heating plate is again removed and the moulded part is ejected by the piston [31]. Since the compression phase is characterized by an increase in the piston force in line with the piston travel, the porosity of the mix is decreased and the particles are subjected to elastic and plastic deformation.…”

“…As shown in Figure 3.8, the tool is heated to the required temperature with the piston in the lower part of the die [31]. The heating plate is removed and a predefi ned volume of the friction material mix is added from above.…”

“…These moulded friction materials are then exposed to additional thermal treatments. This manufacturing process leads to anisotropic and viscoelastic behaviour of the material, as well as a certain amount of heterogeneity [31]. The moulding and heat treatment parameters of brake friction materials can often be chosen based on resin properties specifi ed by the resin manufacturer.…”

“…This is important because the friction material manufacturing industry has always been focused on greater customer satisfaction regarding (i) improved friction stability, (ii) improved life, (iii) absence of judder, (iv) absence of noise and (v) improved rotor compatibility [30]. The manufacture of brake friction materials is a complex process because powder mixes, which contain metal chips, fi lling agents, abrasives and phenolic resins, have to be moulded onto a backplate under pressure and temperature [31]. These moulded friction materials are then exposed to additional thermal treatments.…”