Hot Electromagnetic Forming of Metal Powder Compact and its Application to Combustion Synthesis

Electromagnetic forming have been used in a field of plastic deformation technology of metal materials. In this paper, dynamic compaction of metal powder by electromagnetic forming under hot conditions was attempted in order to investigate a possibility of electromagnetic pressure sintering. After heating in an electric furnace, a copper powder compact was put into a solenoid coil and a strong pulse current from a-condenser bank was passed through the coil.The compact was shrinked and its density was increased by the electromagnetic pressure of the forming. The degree of densification depended on the charged voltage of the condenser, the capacitance, the current wave form of the coil and the forming temperature. Therefore, the forming process would be applicable to powder pressure sintering.The process was applied to combustion synthesis of Ni3AI intermetallic compound. Ni/Al premixed powder compact was compressed by the forming during its thermal explosion reaction. Consequently, the density was improved in comparison to usual combustion synthesis although the synthesized product cracked.