A pilot series of thixopreforms from alloys AK5M, AK7 and AK9 is produced in an experimental casting facility with crystallization under the action of an electromagnetic field. The variable parameters are the temperature of casting of the melt, the circuit of connection of the coils of the electromagnetic mixer, the current frequency in the inductor, and the direction of mixing of the melt. The microstructure of the thixopreforms is determined and the dependences of the parameters of the microstructure on the variable crystallization conditions are obtained.