Effects of ultrasonic field on microstructures and properties of semi-solid AZ91D magnesium alloy

Abstract

The microstructure distribution rule of semi-solid AZ91D alloy treated by ultrasonic was researched, and mechanical properies of specimens before and after ultrasonic treatment were investigated further.Semi-solid AZ91D melt specimens were processed by ultrasonic under different powers, and its microstructures and mechanical properties at different sampling points in specimens were obtained. The experimental results show that the microstructure of AZ91D alloy at different sampling points under the same ultrasonic power is different in grain size and shape, and there is also great difference among their microstructures at the same sampling point under different ultrasonic powers. AZ91D alloy treated by ultrasonic can obtain increment in both tensile strength and plasticity. Under same ultrasonic power, mechanical properties of specimen at different sampling points have obvious difference, and regularity for change of mechanical properties everywhere is similar to regularity for change of grain size and shape everywhere.

Keywords

magnesium alloy AZ91D / ultrasonic treatment / semi-solid structure / distribution rule

References

[1] G I Eskin. Broad Prospects for Commercial Application of the Ultrasonic (Cavitation) Melt Treatment of Light Alloys[J]. Ultrasonics Sonochemistry, 2001, (8): 319–325

[2] Wu S. S., Wu X. P., Xiao Z. H. A Model of Growth Morphology for Semi-solid Metals[J]. Acta Materialia, 2004, 52(12): 3519-3524.

[3] PAN Lei, TAO Jie, CHEN Zhao-feng, et al. Acoustic Effect of High Intensity Ultrasonic in Particles/Metal Melt[J]. Material Engineering, 2006, (1): 35–37, 42

[4] Kang Y.-l., Mao W.-m., Hu Z.-l., . The Semi-solid Process Theory and Technology of the Metal Material[M], 2004 Beijing Science Press 159-161.

[5] Jian X., Xu H. B., Meek T. T., . Effect of Power Ultrasound on Solidification of Aluminum A356 Alloy[J]. Materials Letters, 2005, 59(2–3): 190-193.

[6] Zhao J.-w., Wu S.-sen., Wan L., Chen Q.-h., An Ping. Evolution of Microstructure of Semi-solid Metal Slurry in Ultrasound Field[J]. Acta Metallurgica Sinica, 2009, 45(3): 314-319.

[7] Zhu H.-x., Wang J.-x., Li C., Xiong H.-miao. Effects of Power Ultrasonic Parameters on the Size and Morphology of Primary Phase in Semi-solid A356 Alloy[J]. Special Casting and Nonferrous Alloys, 2008, 28(7): 522-524.

[8] Li J.-w., Momono T., Fu Ying. Effect of Ultrasonic Power on Density and Refinement in Aluminum Ingot[J]. Foundry, 2007, 56(2): 152-154.

[9] Guo H., Yang X.-g., Hu B., Zhu G.-lei. Rheo-diecasting Process for Semi-solid Aluminum Alloys[J]. Journal of Wuhan University of Technology-Materials Science Edition, 2007, 22(4): 590-595.

[10] Liu Q.-m., Gong Y.-y., Hou X., Qi F.-p., Zhai Q.-jie. Influence of Side Ultrasonic Treatment on Solidification Characterization of Al-Si Eutectic Alloy[J]. The Chinese Journal of Nonferrous Metals, 2007, 17(2): 308-312.

[11] Mokusita Okumiya, . Application of Ultrosonic Wave in Aluminium Alloy Semi-solid Slurry Prepared[J]. Foundry Engineering, 2007, 79(2): 95-100.

[12] Chen K.-h., Huang L.-p., Hu H.-w., Liu H.-wei. Effect of Ultrasonic Melt Pretreatment on Structure and Properties of High Strength 7055 Aluminum Alloy[J]. J.Cent. South Univ. (Science and Technology), 2005, 36(3): 354-355.