Fabrication Process and Defect Analysis of Al Matrix Composites for Automobile Brake Discs
Taking the brake disc of a split solid new energy vehicle as object,satisfied pouring process parameters were designed based on the ProCAST simulation results.A hemispherical buffer area was added into the pouring sys-tem to realize the sequence solidification,and the pressure parameters during the stage of vacuum pumping,filling and holding were optimized.The holding time and solidification time were determined as 260 s and 180 s,respectively,and the brake disc body with well surface was cast by mechanical stirring method.Defect analysis reveals that the local coarse dendrite crystals exist in the matrix,and the particle accumulation at the front of filter reaches 30%(volume fraction),while the SiC content in the matrix after filtration is only 18%.After changing mechanical stirring to ultrasonic-electromagnetic stirring,coarse dendrites in the disc are broken,and SiC particles are evenly dispersed with content of 20%,within the technical category.
Al Matrix CompositesDefect AnalysisUltrasonic-electromagnetic Stirring
NETL
NSTL
万方数据
