STRUCTURE EVOLUTION OF ZINC ALUMINUM ALLOYS IN THE SEMISOLID STATE

WILKY DESROSIN; CARLOS E. SCHVEZOV; MARIO R. ROSENBERGER; ALICIA E. ARES

Sao Paulo, Brasil

Conferencia; PAN AMERICAN MATERIALS CONFERENCE 2014 - Light Metals and Alloys Symposium; 2014

Asociación Brasilera de Materiales (ABM)

Semi-solid processing of alloys is an alternative to regular casting for small components at a lower cost. The SIMA process has been developed and used for semisolid process of ZA27 alloys. The optimun processing route requires the control of the semi-solid structure to be at a specific solid fraction and size of the solid grains. In order to investigate the process of ZA alloys in a range of compositions experiments were carried out with the more common with the more common alloy as the ZA27. Cast alloys of ZA27 were deformed between 30 to 80 % by compression and heat treated at two temperatures of 440 ºC and 445 ºC in the mushy region during total periods of time between 45 min to 360 min. The heat treatment was discontinuos and the samples were polished and analyzed after each step. The results are presented showing that for this alloy a thermal treatment at 445 ºC produce a better semisolid structure that at 440 ºC. The effect of degree of deformation, temperature and time of treatment on microstructure evolution including solid fraction, size distribution and alfa and beta phases distribution and fraction is determined and analyzed.