Effect of Cooling Rate on Microstructure of Semi-Solid AZ61 Slurry Produced via Ultrasonic Vibration Process

Abstract:

The semi-solid metal (SSM) processing, including thixoforming and rheocasting, offers the opportunity to manufacture net-shaped components with complicated shape and good mechanical properties. More and more researches have been focused on rheocasting in recent years because of its low cost and high productivity [1,. Rheocasting involves stirring the solidifying alloy to prepare non-dendritic semisolid slurry, then shaping the slurry directly. Ultrasonic vibration (USV) has the potential to be a simple and effective process to produce semisolid metal slurry. Previous investigations have revealed that when USV is applied on the solidifying melt, microstructure changes occur involving grain refinement, increased homogeneity, reduced micro-segregation as well as degassing [3-.

• Periodical: Advanced Materials Research (Volumes 750-752)
• Pages: 696-700
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.750-752.696
• Online since: August 2013
• Authors: Jun Ping Yao*, Zhong Sun, Wen Yuan Long, Lei Zhang
• Keywords: AZ61 Alloy, Cooling Rate, Microstructure, Semi-Solid, Ultrasonic Vibration

References

[1] Wannasin J, Canyook R, Burapa R, Sikong L, Flemings MC. Evaluation of solid fraction in a rheocast aluminum die casting alloy by a rapid quenching method. Scr Mater 2008; 58: 1091-4.

DOI: 10.1016/j.scriptamat.2008.07.029

[2] Wu S, Xie L, Zhao J, Nakae H. Formation of non-dendritic microstructure of semisolid aluminum alloy under vibration. Scr Mater 2008; 58: 556-9.

DOI: 10.1016/j.scriptamat.2007.11.010

[3] Jian X, Xu H, Meek TT, Han Q. Effect of power ultrasound on solidification of aluminum A356 alloy. Mater Lett 2005; 59: 190-3.

DOI: 10.1016/j.matlet.2004.09.027

[4] Abramov V, Abramov O, Bulgakov V, Sommer F. Solidification of aluminium alloys under ultrasonic irradiation using water-cooled resonator. Mater Lett 1998; 37: 27-34.

DOI: 10.1016/s0167-577x(98)00064-0

[5] Das A, Kotadia HR. Effect of high-intensity ultrasonic irradiation on the modification of solidification microstructure in a Si-rich hypoeutectic Al–Si alloy. Mater Chem Phys 2011; 125: 853-9.

DOI: 10.1016/j.matchemphys.2010.09.035

[6] Wu S S, Lu S L, An P, Naae H. Microstructure and property of rheocasting aluminum-alloy made with indirect ultrasonic vibration process. Mater Lett 2012; 73: 150-153.

DOI: 10.1016/j.matlet.2012.01.040

[7] Lȕ S L, Wu S S, Zhu Z M, An Ping, Mao Y W. Effect of semi-solid processing on microstructure and mechanical properties of 5052 aluminum alloy. Transactions of Nonferrous Metals Society of China, 2010, 20(s): s758-s762.

DOI: 10.1016/s1003-6326(10)60577-8

[8] Zhang Z Q, Le Q C, Cui J Z. Influence of high-intensity ultrasonic treatment on the phase morphology of a Mg_9. 0wt. %Al binary alloy. Rare Met 2009; 28: 86-90.

DOI: 10.1007/s12598-009-0017-3

[9] Liu X B, Osawa Y, Takamori S, Mukai T. Grain refinement of AZ91 alloy by introducing ultrasonic vibration during solidification. Mater Lett 2008; 62: 2872-2875.

DOI: 10.1016/j.matlet.2008.01.063

[10] Lan J, Yang Y, Li X C. Microstructure and microhardness of SiC nanoparticles reinforced magnesium composites fabricated by ultrasonic method. Mater Sci Eng A 2004; 386: 284-290.

DOI: 10.1016/s0921-5093(04)00936-0