The Microstructure of Direct Squeeze Cast and Gravity Die Cast 7050 (Al–6.2Zn–2.3Cu–2.3Mg) Wrought Al Alloy
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
A 7050 (Al–6.2 wt% Zn–2.3 wt% Cu–2.3 wt% Mg) Al alloy, conventionally used for wrought products, has been successfully cast to near-net shape using direct squeeze casting. Squeeze casting with an applied pressure of 50 MPa removes the defects observed in gravity die cast billets, in particular, (1) shrinkage pipe, (2) poor die replication and waisting, and (3) microporosity. Squeeze casting results in considerable refinement of the microstructure due to an increase in cooling rate from ∼0.5°C s−1 for gravity casting to ∼11°C s−1 for squeeze casting in a tool steel die lined with porous insulation, and from ∼2.5 to ∼10°C s−1, respectively, in an uninsulated die. A normal segregation pattern of increasing eutectic toward the center of the billet is found for squeeze casting, compared to an inverse segregation pattern of increasing eutectic toward the edge of the billet for gravity casting. This change in segregation pattern is due to a higher radial temperature gradient and reduced time in the semisolid state for squeeze casting.
- G. A. Chadwick and T. M. Yue, Met. Mater. 5, 6 (1989).
- Product Design and Specifications for Squeeze Casting (ELM International Inc., East Lansing, MI, 1994).
- M. Gallerneault, G. Durrant, and B. Cantor, Met. Trans. A 27A, 4121 (1996).
- Metals Handbook, 9th ed. (ASM, Metals Park, OH, 1979).
- D. L. Zhang, C. Brindley, and B. Cantor, J. Mater. Sci. 28, 2267 (1993).
- J. Campbell, Castings (Butterworth-Heinemann, Oxford, UK, 1991).
- I. J. Polmear, Light Alloys, 2nd ed. (Edward Arnold, London, 1989).
- M. F. Flemings, Solidification Processing (McGraw-Hill, London, 1974).
- D. L. Zhang and B. Cantor, Model. Simul. Mater. Sci. Eng. 3, 121 (1995).
- J. A. Sekhar, G. J. Abbaschian, and R. Mehrabian, Mater. Sci. Eng. 40, 105 (1979).
- M. Gallerneault, G. Durrant, and B. Cantor, Scripta Met. 32, 1553 (1995).
- G. S. Reddy and J. A. Sekhar, Acta. Metall. 37, 1509 (1989).
- G. S. Reddy and J. A. Sekhar, Principles of Solidification and Materials Processing, Vol. 1 (Oxford and IBH, Oxford, IBSN 81-204-0448-3, 1989).
- J. H. Perepezko, Mater. Sci. Eng. 65, 125 (1984).
- The Microstructure of Direct Squeeze Cast and Gravity Die Cast 7050 (Al–6.2Zn–2.3Cu–2.3Mg) Wrought Al Alloy
Journal of Materials Synthesis and Processing
Volume 6, Issue 2 , pp 75-87
- Cover Date
- Print ISSN
- Online ISSN
- Kluwer Academic Publishers-Plenum Publishers
- Additional Links
- Squeeze casting
- Al alloy