The behavior of ceramic particles at the solid/liquid interface and the distribution of particles in metallic matrix composites was studied with a zone unidirectional solidification method. Two kinds of partice disper...The behavior of ceramic particles at the solid/liquid interface and the distribution of particles in metallic matrix composites was studied with a zone unidirectional solidification method. Two kinds of partice dispersed composites, Al 2O 3P /Al 12.6%Si Sr and Al 2O 3P /Al 12.6%Si Sr Ca containing Al 2O 3 particles in volume fraction 2%～5% were used. In the Al 2O 3P /Al Si Sr composites, the particles were pushed by the solidifying front, and did not uniformly distribute in the solid. But in the Al 2O 3P /Al Si Sr Ca composites, the particles were engulfed by the solidifying front and uniformly distributed in the solid. The particles engulfing into the solid was realized only by Sr and Ca addition at the same time. As the interfacial energy between solid and particle was decreased in this case, the Al 2O 3 particles acted as the substrates of heterogeneous nucleation for the Si phases, which made the particles to be engulfed.展开更多
文摘The behavior of ceramic particles at the solid/liquid interface and the distribution of particles in metallic matrix composites was studied with a zone unidirectional solidification method. Two kinds of partice dispersed composites, Al 2O 3P /Al 12.6%Si Sr and Al 2O 3P /Al 12.6%Si Sr Ca containing Al 2O 3 particles in volume fraction 2%～5% were used. In the Al 2O 3P /Al Si Sr composites, the particles were pushed by the solidifying front, and did not uniformly distribute in the solid. But in the Al 2O 3P /Al Si Sr Ca composites, the particles were engulfed by the solidifying front and uniformly distributed in the solid. The particles engulfing into the solid was realized only by Sr and Ca addition at the same time. As the interfacial energy between solid and particle was decreased in this case, the Al 2O 3 particles acted as the substrates of heterogeneous nucleation for the Si phases, which made the particles to be engulfed.
