Effect of solid solution treatment on semisolid microstructure of dendritic zinc alloy ZA27

Abstract

The effect of solid solution treatment on semisolid microstructure of a Zn alloy ZA27 with developed dendrites was investigated and a new approach to produce non-dendritic semisolid microstructure available for thixoforming was developed. The results indicated that a semisolid microstructure with small and spherical primary particles could be obtained when the alloy with developed dendrites was solution treated for 3 h at 370uC and then partially remelted at a semisolid temperature of 460uC. This method could not only overcome some inevitable shortcomings resulting from using some present popular approaches, but also simplify the procedure of thixoforming. Too short or too long solution treatment duration could increase the shape factor, size and inhomogeneity of the primary particles. All of these microstructural changes were attributed to the dendrite coalescence and phase transformation which occurred during solid solution treatment.

Corrosion and Wear Performance of Za27/Graphene/B4c Hybrid Nanocomposites Produced by Powder Metallurgy

“…B4C and graphene powders (Alfa Aesar) with an average particle size of 50 nm and 55 nm were employed as reinforcement materials. The nominal composition of the ZA27 alloy listed in Table 1 [20,21]. Table 2 shows the coded of hybrid nanocomposites and their reinforcement content.…”

Microstructural evolution and phase transformations during partial remelting of AZ91D magnesium alloy refined by SiC

“…Only a few papers have involved the as-cast magnesium alloys, but emphasized on the morphology change and coarsening behavior of the primary particles or the Mg 2 Si particles in Si containing alloys in semisolid sate [19][20][21][22][23][24][25]. However, the microstructural evolution prior to liquid forming is very important for the final semisolid microstructure [26]. Furthermore, the relationship between the as-cast microstructure and semisolid microstructure is still unclear.…”

Real time investigation of the grain refinement dynamics in zinc alloy by synchrotron microradiography

“…Commercial ZA27 alloy, the nominal composition of which is listed in Table 1, was selected as the candidate for grain refinement tests. On the one hand, it is one of the most widely used commercial casting zinc alloy [14,15] to give better image contrast for the large differences in their X-ray attenuation lengths [16]. Furthermore, ZA27 alloy is well known for good fluidity and low melting temperature which will lead to a simplified experiment device.…”