The solidification in the presence of a metastable miscibility gap: the case of Co-Cu and Co-Cu-X alloys

TY - JOUR

T1 - The solidification in the presence of a metastable miscibility gap

T2 - the case of Co-Cu and Co-Cu-X alloys

AU - Battezzati, L.

AU - Johnson, Erik

AU - Pryds, Nini

AU - Penna, A.

AU - Stefano, C.

PY - 2010/5/1

Y1 - 2010/5/1

N2 - Alloys displaying positive enthalpy of mixing demix below a critical temperature. In Co-Cu and related ternaries the miscibility gap is metastable, i.e. it occurs at temperatures lower than the liquidus. In order to study the liquid phase separation high melt undercooling is necessary. This was obtained via rapid solidification techniques using melt spinning and casting in moulding devices, as well as high temperature DSC experiments with samples embedded in a flux. Results are given for Co-Cu, Co-Cu-Fe and Co-Cu-Ni systems. Phase diagrams were optimised using the DSC data. The mechanism of phase separation was investigated by comparing samples produced under different cooling conditions. The hierarchy of microstructures obtained was interpreted accounting for the processing technique and the phase diagram. They constitute a database useful for the interpretation of the thermal history of samples processed in microgravity.

AB - Alloys displaying positive enthalpy of mixing demix below a critical temperature. In Co-Cu and related ternaries the miscibility gap is metastable, i.e. it occurs at temperatures lower than the liquidus. In order to study the liquid phase separation high melt undercooling is necessary. This was obtained via rapid solidification techniques using melt spinning and casting in moulding devices, as well as high temperature DSC experiments with samples embedded in a flux. Results are given for Co-Cu, Co-Cu-Fe and Co-Cu-Ni systems. Phase diagrams were optimised using the DSC data. The mechanism of phase separation was investigated by comparing samples produced under different cooling conditions. The hierarchy of microstructures obtained was interpreted accounting for the processing technique and the phase diagram. They constitute a database useful for the interpretation of the thermal history of samples processed in microgravity.

U2 - 10.4028/www.scientific.net/msf.649.41

DO - 10.4028/www.scientific.net/msf.649.41

M3 - Journal article

SN - 0255-5476

VL - 649

SP - 41

EP - 45

JO - Materials Science Forum

JF - Materials Science Forum

IS - 41

ER -