Process Development and Grain Refinement
Haghayeghi, E.J. Zoqui, “Process Development and Grain Refinement”, Journal of La Metallurgia Italiana, Vol.108, 2016, PP.149-152.
The effect of Ultrasonic Treatment (UT) and Electro Magnetic Stirring (EMS) were assessed separately and in combination prior to high pressure die-casting of AA5754. Results suggested by utilization of UT the grain size is reduced from 140 μm to 80 μm, while the porosity decreased from 5.5% down to 1.6%. Application of EMS reduced the grain size and porosity to 109 μm and 4.5%, respectively. However, the combination of UT and EMS decreased the grain size to 65 μm and porosity content to 1%. The intensive cavitation fields of both sources and appropriate stirring improved the formation of equiaxed microstructure. EMS enhanced nucleation process by providing ample exogenous particles in the strong field of UT. The mechanical property evaluation and the acquired gas content indicate UT is enough for acquiring desirable characteristics