|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Cast Shop Technology
||Effect of Ultrasonic Melt-treatment and Cooling Rate on Microstructure of Multi-phase Reinforced Al Alloy
||Kwangjun Euh, Jae-Gil Jung, Ju-Hye Kim, Eun-Ji Baek, Jung-Moo Lee
|On-Site Speaker (Planned)
Al-xMg-10Si-10Cu-10Zn (in wt%) alloy is fabricated with a high volume fraction of coarse multi-phase particles in the aluminum matrix. Permanent mold casting is carried out with a selective ultrasonic melt-treatment for 60 sec at 1000 K. A step mold is used to achieve three different kinds of cooling rate. Blocky primary Mg2Si particles are homogeneously distributed through the Al matrix and eutectic phases such as Si, Q-Al5Cu2Mg8Si6, and θ-Al2Cu are found in the dendritic boundaries. The ultrasonication significantly decreased the porosity and the size of microstructural constituents such as primary Mg2Si phases. Refinement of primary Mg2Si by ultrasonication is more effective in the specimens with higher cooling rate. The compressive properties at room temperature and 623 K are enhanced in the ultrasonicated alloys. By heat treatment at 713 K, very ﬁne θ’ precipitates with size less than 10 nm were formed through the Al matrix and blocky Mg2Si and Q phases were spheroidized.
||Planned: Light Metals