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Although the radial migration of hot bands has been frequently observed, a systematic investigation of this phenomenon has not yet been performed. The ring-shaped temperature maximum, which occurs on the brake disk, is undesirable because the focused temperatures destroy the local materials in contact. Moreover, a hot band carries a dominant portion of the frictional load. If a hot band moves radially, the braking torque is directly influenced. It is supposed that material wear influences the radial hot band migration. New models demonstrate that wear is indeed the mechanism that triggers hot band migration. First, a minimal model including thermal expansion and a load-dependent loss of material is introduced. The simplicity of the model allows for an understanding of the impact of wear, as well as the mechanisms that lead to a periodic load distribution. This model can be analyzed in terms of complex eigenvalues, showing a periodic load distribution in the sliding plane.

Although the aspect of wear is generally of high importance in the development of brake materials, a prediction of the wear characteristics, the wear distribution and the wear rate is nearly impossible up to date. This problem has several reasons. Taking a look into the interface dynamics between disc and pad, the growth and destruction of hard and thin structures, so-called “patches” can be found. These patches protect the softer pad ingredients from wear, so wear is not homogeneously distributed in the interface. Thus for the comprehension of the wear-determining parameters this process has to be understood. This paper dedicates to this question and identifies some material-design criteria with respect to wear rates.