Microstructure and properties of 5083(Er) aluminium alloy prepared by low frequency electromagnetic casting

The overburning behavior and microstructure and mechanical properties of low frequency electromagnetic cast 5083 (Er) aluminium alloy homogenized at different temperatures were investigated by means of DSC analysis,conductivity measurement,tensile test,OM,XRD,TEM,SEM and EDS.The results show that with increasing homogenizing temperature,the ultimate tensile strength increases and reaches a maximum value at 510 ℃ and then decreases slightly,the conductivity increases and reaches a maximum value at 490 ℃ and keeps it till 520 ℃ ,while decreases significantly at 540 ℃ .The incipient melting temperature of the 5083(Er) alloy is 540 ℃ determined by microstructural observations,DSC analysis and conductivity measurement.Plenty of MnAl6 /FeMnAl6 rods with size of 100-700 μm are observed when homogenizing temperature is lower than 470 ℃ .Many extremely fine ErAl3 particles with size of 5-20 nm preferentially precipitate along dislocations in the sample homogenized at 490 ℃ .The amount of MnAl6 /FeMnAl6 rod and ErAl3 particles increases significantly when homogenizing temperature is 510 ℃ ,and then decreases due to coarsening of the phases with increasing homogenizing temperature.