INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Correlation between Thermal Parameters, Structures, Dendritic Spacing and Corrosion Behavior of Zn-Al Alloys with Columnar to Equiaxed Transition
Autor/es:
A. E. ARES; L.M. GASSA; S. F. GUEIJMAN; C. E. SCHVEZOV
Revista:
JOURNAL OF CRYSTAL GROWTH
Editorial:
Elsevier
Referencias:
Lugar: Salt Lake City, Utah; Año: 2008 vol. 310 p. 1355 - 1361
ISSN:
0022-0248
Resumen:
The columnar to equiaxed transition (CET) has been examined for many years and the significance of CET has been treated in several
articles. Experimental observations in different alloy systems have shown that the position of the transition is dependent on parameters
like cooling rate, velocity of the liquidus and solidus fronts, local solidification time, temperature gradients and recalescence. The
dendritic structure in alloys results in microsegregation of solute species which affects significantly the mechanical properties of the
material. The main parameters characterizing the microstructure and the length range of microsegregation is the spacing which is
classified as primary, secondary and tertiary. Properties like mechanical resistance and ductility are influenced by the dimensions and
continuity of the primary branches, while the secondary and tertiary branches permit the isolation of interdendritic phases which can
deteriorate the mechanical behavior of the material. Since the morphology and dimensions of the dendritic structure is related to the
solidification parameters mentioned above, for each type of alloy it is essential to correlate dimensions and solidification conditions in
order to control the structure. The objective of the present research consists on studying the influence of solidification thermal parameters
with the type of structure (columnar, equiaxial or with the CET); and with grain size and dendritic spacing (primary and secondary) in
ZnAl (ZA) alloys (Zn4 wt%Al, Zn16 wt%Al and Zn27 wt%Al, weight percent). Also, correlate the thermal parameters, type of
structure, grain size and dendritic spacing with the corrosion resistance of these alloys.