2003 Volume 44 Issue 4 Pages 595-600
Magnesium based porous materials are made by Pulse-Electric-Current-Sintering (PECS) method using cut chips. Commercial ingots of AZ91D and AM60B alloys and extruded AZ31 alloy were selected as raw materials in order to change the amount of eutectic compounds and the range of semi-solid temperatures. Porous materials of various plateau stresses could be made by PECS process depending on pore ratio, alloy composition and sintering temperature. In well-joined parts of porous samples of AZ91D and AM60B alloy, Mg–Al system compounds crystallize, while the aluminum content at the joined part of AZ31 porous sample is concentrated. This means that the non-equilibrium solidified Mg–Al compound is preferentially remelted by rapid heating during PECS. Thus the difference in the microstructures of the joined parts is caused by the different aluminum contents of the alloys. The condition for making the well-joined porous materials using PECS process is to use alloys that have large amount of low melting compounds and large semi-solid temperature range. The plateau stresses of the porous materials investigated in this study are in the range from 1.3 to 37.3 MPa and pore ratio is the most important factor affecting plateau stress.
