This practice covers the requirements for the heat treatment of aluminum alloy castings from any casting process such as investment casting, permanent mould casting, sand casting, and others. It excludes castings that are used in specific aerospace applications or those made from wrought aluminum alloys. The aluminum alloys should be subjected to controlled heat treatment using the usual air chamber furnace or other heating media like lead baths, oil baths, fluidized beds, or even superheated steam. Air chambers may be oil or gas fired or may also be electrically heated but the atmosphere inside each should be controlled to prevent porosity. Quenching is normally performed by immersing castings in a hot-water bath. It is important that the furnace be calibrated before it is used initially and after any change in the furnace. Likewise, temperature-measurement systems should be regularly checked for accuracy.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This practice covers, when specified by material specification or purchase order, the heat treatment of aluminum alloy castings from all casting processes.

1.1.1 The heat treatment of aluminum alloy castings used in specific aerospace applications is covered in AMS 2771 and specific AMS material specifications.

1.1.2 The heat treatment of wrought aluminum alloys is covered in Practice B918/B918M.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.2.1 SI Units—The SI units are shown in brackets or in separate tables.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

B26/B26M Specification for Aluminum-Alloy Sand Castings

B108/B108M Specification for Aluminum-Alloy Permanent Mold Castings

B275 Practice for Codification of Certain Nonferrous Metals and Alloys, Cast and Wrought

B557 Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products

B557M Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products (Metric)

B618/B618M Specification for Aluminum-Alloy Investment Castings

B686/B686M Specification for Aluminum Alloy Castings, High-Strength

B881 Terminology Relating to Aluminum- and Magnesium-Alloy Products

B918/B918M Practice for Heat Treatment of Wrought Aluminum Alloys

B955/B955M Specification for Aluminum-Alloy Centrifugal Castings

B969 Specification for Aluminum-Alloy Castings Produced by the Squeeze Casting, Thixocast and Rheocast Semi-Solid Casting Processes

G110 Practice for Evaluating Intergranular Corrosion Resistance of Heat Treatable Aluminum Alloys by Immersion in Sodium Chloride + Hydrogen Peroxide Solution

ANSI Standard

SAE Standard

Keywords

aluminum alloys; centrifugal casting; investment casting; permanent mold casting; precipitation heat treatment; rheocast casting; sand casting; solution heat treatment; squeeze casting; thixocast casting;

ICS Code

ICS Number Code 25.200 (Heat treatment); 77.150.10 (Aluminium products)

Citing ASTM Standards

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