Potency of high-intensity ultrasonic treatment for grain refinement of magnesium alloys

High-intensity ultrasonic treatment (UT) for grain refinement of magnesium alloys has been investigated using a novel theoretical approach in order to better understand its grain-refining potential and the mechanism of nucleation. The process demonstrated significantly superior grain-refining potency to carbon inoculation for Al-containing magnesium alloys but inferior potency to zirconium for Al-free alloys. Details revealed by applying the theoretical approach to ultrasonic grain refinement provide new clues to understanding the mechanism of grain nucleation by UT.

[1]  M. Flemings.  Solidification processing , 1974, Metallurgical and Materials Transactions B.

[2]  D. StJohn,et al.  A New Analytical Approach to Reveal the Mechanisms of Grain Refinement , 2007 .

[3]  P. Cooper,et al.  Effects of solutes on grain refinement of selected wrought aluminium alloys , 1997 .

[4]  J. Hunt,et al.  Nucleation of Solid in an Undercooled Liquid by Cavitation , 1966 .

[5]  Q. Le,et al.  Ultrasonic Treatment of Magnesium Alloy Melts and its Effects on Solidification Microstructures , 2007 .

[6]  D. StJohn,et al.  A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleant particles , 2001 .

[7]  David H. StJohn,et al.  Grain refinement of aluminum alloys: Part II. Confirmation of, and a mechanism for, the solute paradigm , 1999 .

[8]  M. Qian,et al.  Discussions on grain refinement of magnesium alloys by carbon inoculation , 2005 .

[9]  M. Qian.  HETEROGENEOUS NUCLEATION ON POTENT SPHERICAL SUBSTRATES DURING SOLIDIFICATION , 2007 .

[10]  Theory of catalysis of nucleation by surface patches , 1953 .

[11]  D. StJohn,et al.  Grain refinement of magnesium alloys , 2005 .

[12]  O. V. Abramov,et al.  Ultrasound in Liquid and Solid Metals , 1994 .

[13]  E. F. Emley.  Principles of magnesium technology , 1966 .

[14]  C. Brennen.  Cavitation and Bubble Dynamics , 1995 .

[15]  Tobias J. Hagge,et al.  Physics , 1929, Nature.

[16]  M. Qian.  Creation of semisolid slurries containing fine and spherical particles by grain refinement based on the Mullins–Sekerka stability criterion , 2006 .

[17]  M. Johnsson.  Influence of Si and Fe on the Grain Refinement of Aluminium , 1994 .