Cooling Behavior and Microstructure of Semisolid A201 Aluminum Alloy Prepared by the SEED Process

Abstract

The biggest challenge in semisolid processing of high-performance aluminum alloys is the narrow temperature processing windows of these alloys, and as a result, the preparation of qualified semisolid slurries is very important. High solid fraction slurries of high-strength A201 alloy were prepared by the Swirled Enthalpy Equilibration Device (SEED) process. The cooling behavior and microstructures of the A201 slurries produced by the standard, as well as a modified, SEED process were investigated. The results show that qualified A201 slurry can be produced by decreasing the pouring temperature and controlling the processing time in the SEED process. The modified SEED process significantly reduced the radial temperature gradient of the melt, due to the slow cooling rates involved, with the resulting slurries being more uniform, with more spherical microstructures, as compared to those produced by the standard SEED process. The formation of the nondendritic grain structure in the SEED process is attributed to the uniformly distributed large number of nuclei within the melt and the slow cooling of the melt in the containing crucible.

Recent Industrial Application and Perspectives of Rheo-Diecast Process in China

“…Recently, rheo-diecasting process has also been categorized into two processes according to the solid fraction content of the slurries: the high solid fraction process with about 40-60% of solid, and the low solid fraction process with around 5-20% of solid [3]. An example of the high solid fraction semisolid diecasting process is SEED (Swirled Enthalpy Equilibrium Device) [4], while lots of low solid fraction processes such as the gas-induced semisolid (GISS) rheo-casting, new rheo-casting (NRC), air-cooled stirring rod (ACSR) process, forced convection stirring (FCS) and so on [5].…”

Effects of Isothermal Temperature and Soaking Time on Water Quenched Microstructure of Nickel-Based Superalloy GH3536 Semi-Solid Billets

“…It combines both the advantages of casting and forging, and can form parts with good comprehensive performance and complex geometry. Recently, many aluminum and magnesium products have been fabricated by semi-solid forming [ 8 , 9 , 10 , 11 ], especially in the field of producing automotive parts. However, the SSP method of high melting point alloys has not received widespread attention because of the high semi-solid temperatures.…”