The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 1991
Filed:
Dec. 01, 1989
Venkatasubramanian Laxmanan, Troy, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A semi-solid metal-forming process for producing an article of a hypoeutectic aluminum-silicon alloy comprises heating a solid billet of the alloy to a temperature intermediate the liquidus temperature and the solidus temperature at a rate not greater than 30.degree. C. per minute, preferably not greater than 20.degree. C. per minute, to form a semi-solid body of the alloy while inhibiting the formation of free silicon particles therein. The semi-solid body comprises a primary spheroidal phase dispersed in a eutectic-derived liquid phase and is conducive to forming at low pressure. In one apsect of this invention, a billet having a quiescently cast microstructure characterized by primary dendrite particles in a eutectic matrix is heated at the slow rate and maintained at the intermediate temperature for a time sufficient to transform the dendrite phase into the desired spheroidal phase.