Aluminum-silicon alloy having reduced microporosity

Details Aluminum-silicon alloy having reduced microporosity Aluminum-silicon alloy having reduced microporosity

2005-01-25

2010-02-23

King, Roy (Department: 1793)

Alloys or metallic compositions

Aluminum base

Silicon containing

C420S549000

Reexamination Certificate

active

07666353

ABSTRACT:
An aluminum silicon die cast alloy having a very low iron content and relatively high strontium content that prevents soldering to dies into die casting process. The alloys of the present invention also have a modified eutectic silicon and modified iron morphology, when iron is present, resulting in low microporosity and high impact properties. The alloy comprises 6-22% by weight silicon, 0.05 to 0.20% by weight strontium and the balance aluminum. Preferably, the alloy of the present invention contains in weight percent: 6-20% silicon, 0.05-0.10% strontium, 0.40% maximum iron and most preferably 0.20% maximum iron, 4.5% maximum copper, 0.50% maximum manganese, 0.60% maximum magnesium, 3.0% maximum zinc, balance aluminum. On cooling from the solution temperature, the strontium serves to modify the eutectic silicon structure as well as create an iron phase morphology change if iron is present, facilitating feeding through the aluminum interdendritic matrix. This, in turn, creates a finished die cast product with extremely low levels of microporosity defects. The strontium content also appears to create a non-wetting monolayer of strontium atoms on the surface of a molten casting, preventing die soldering, even at very low iron contents. The alloy may be used to cast any type of object and is particularly suited for casting outboard marine propellers, driveshaft housings, gear case housings, Gimbel rings and engine blocks.

REFERENCES:
patent: 4969428 (1990-11-01), Donahue et al.
patent: 5009844 (1991-04-01), Laxmanan
patent: 5023051 (1991-06-01), Lindburg
patent: 5045110 (1991-09-01), Vader et al.
patent: 5234514 (1993-08-01), Donahue et al.
patent: 6139654 (2000-10-01), Boone et al.
patent: 6221504 (2001-04-01), Pfeffinger et al.
patent: 6267829 (2001-07-01), Backerud et al.
patent: 6355213 (2002-03-01), Takasaki et al.
patent: 6364970 (2002-04-01), Hielscher et al.
patent: 6402860 (2002-06-01), Hashikura et al.
patent: 6773666 (2004-08-01), Lin et al.
patent: 6923935 (2005-08-01), Donahue et al.
patent: 0 813 922 (1997-12-01), None
patent: WO-89/07662 (1989-08-01), None
patent: WO-96/27686 (1996-09-01), None
“Aluminum and Aluminum Alloys”, ASM International, 1993, p. 88-101.
“Huttenaluminium-Gusslegierungen”, Aluminium Rheinfelden GmbH, Edition Nov. 1994.
Typical and Minimum Mechanical Properties of Aluminum Alloy Castings, J. Gilbert Kaufman et al., Aluminum Alloy Castings—Properties, Processes, and Applications, AFS and ASM International, Copyright 2004, p. 71.
Selection and Application of Aluminum Alloys, ASM Specialty Handbook, Aluminum and Aluminum Alloys, J. R. Davis, Copyright 1993, pp. 89-91, 110, 113-114.
The Treatment of Liquid Aluminum-Silicon Alloys, The American Foundrymen's Society, Inc., John E. Gruzleski, Copyright 1990, pp. 36, 38, 45, 48-49, 54, 80, 180, 184.
Solidification of Castings, Foundry Engineering, Department of Metallurgy Massachusetts Institute of Technology, Howard F. Taylor et al., Copyright 1959, pp. 119, 121.
Factors to Consider About Diecasting, Aluminum Casting Technology, 2nd Edition, John L. Jorstad et al., Copyright 1993, p. 13.
Production Techniques 2—Shell, Investment and Die Casting, Foundry Technology, P. R. Beeley, Copyright 1972, p. 480.
Casting and Aluminum and Its Alloys, The Aluminum Industry in Two Volumes, Chemical Engineering Series, Junius Davie Edwards, Copyright 1930, p. 331.
Assessment of the Influence of Slow to Fast Shot Transition Point on Cavity Filling Patterns in Cold Chamber Die Casting, Nadca Technical Guidebook Project Summary, J. Brevick, Aug. 30, 2000, 4 pgs., www.diecasting.org.
Strontium as a modifying agent for Al-Si eutectic alloy, P. Davami et al., British Foundryman, vol. 72, No. 4, 1979, pp. 4-7.
Effect of variation of Aluminum-alloy chemistry(titanium and strontium additions)on die/molten metal interface interactions, Proceedings of the 5th International Molten Metal Conference, 1998, pp. 211-230, XP009064953.
The influence of strontium on porosity formation in Al-Si alloys, Metallurgical and Materials Transactions A, vol. 35A, 2004, pp. 3531-3541, XP00906493.
Mechanism and preventive measures for die soldering during AI casting in a ferrous mold, JOM, Minerals metals & materials Society, Warrendale, PA, US, vol. 54, No. 8, Aug. 2002, pp. 47-54, XP001246601.
Aluminum and aluminum alloys, 1993, ASM International, Materials Park, OH, pp. 97-99, XP002376502.
“Aluminum and Aluminum Alloys” ASM Specialty Handbook, Copyright 1993.
“Solidification Characteristics of Aluminum Alloys,” vol. 2, Foundry Alloys, Copyright 1990.
“Aluminum Properties and Physical Metallurgy,” American Society for Metals, Copyright 1984.
“Advanced Casting Research Center, Consortium Meeting, May 25, 2004,” Report 04-#1, Metal Processing Institute.
“Aluminum Handbook,” vol. 1: Fundamentals and Materials, First Edition, Aluminum-Verlag Marketing & Kommunikation GmbH, 1999.
“The Physical Properties of Liquid Metals,” Takamichi Iida & Roderick I.L. Guthrie, Clarendon Press-Oxford 1988.
Olsen, D.A. and Johnson, D.C. (1963), J. Phys. Chem. 67, 2529.

Affiliated with

Also associated with

Rating

Aluminum-silicon alloy having reduced microporosity does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Aluminum-silicon alloy having reduced microporosity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aluminum-silicon alloy having reduced microporosity will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4220650