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

Get Certified ASTM B557 Testing for Reliable Tensile Property Evaluation.

ASTM B557 testing provides useful information about the tensile strength and ductility of aluminum- and magnesium-alloy products. This way, engineers can test a material’s reaction to controlled tensile loading. The test is conducted by applying a force to a prepared specimen until yielding and fracture occur, and the force and deformation are recorded by the testing equipment. This information is utilized to compare materials, aid in the development of alloys, assess product quality, and assist in engineering design.

• Material: Wrought and cast aluminum- and magnesium-alloy products.
• Test method: Tension testing of metallic alloy products under uniaxial tensile loading.
• Specimens: Standardized tensile specimens prepared from applicable product forms.
• Mechanical properties: Evaluation of strength and ductility through tensile testing.
• Product forms: Testing of applicable sheet, plate, bar, rod, extrusion, tubular, forging, wire, and cast products.
• Units: Inch-pound units serve as the standard reporting basis.
• Foil limitation: Aluminum foil is excluded from the scope; foil is defined as sheet metal less than 0.0079 inches thick.
• Acceptance testing: The test methods are considered satisfactory for acceptance testing of commercial shipments.

What are the Uses of ASTM B557 Testing?

ASTM B557 testing is performed to determine the strength and ductility of products made of aluminum and Magnesium alloys when subjected to uniaxial tensile stresses. Therefore, manufacturers and engineers can compare materials and determine their mechanical properties. This method can also be used to develop alloys, for quality control, engineering design, and commercial shipment acceptance. The ASTM B557 standard-

• Measures the strength of the alloy materials.
• Calculates the yield strength if applicable.
• Measures elongation and reduction of area if necessary.
• Compares aluminum and Magnesium alloys.
• Helps with the development of an alloy.
• Supports quality-control evaluations.
• Supplies engineering design information.
• Assists in acceptance tests of commercial deliveries.

Which materials can be tested under ASTM B557?

ASTM B557 covers wrought and cast aluminum- and magnesium-alloy products. These products may include sheet, plate, bar, rod, extrusion, tubular products, forgings, wire, and cast products when the applicable specimen requirements can be met. Thus, the method can be used to assess tensile strength and ductility of various product forms of aluminum and magnesium alloys.

Why is ASTM B557 Important?

ASTM B557 is important as it is a tensile test that gives data regarding the strength and ductility of materials under uniaxial tensile stresses. The method provides uniform procedures for preparation and testing of specimens. This means that engineers can obtain a consistent piece of information for material comparison, alloy development, quality control, and design. The test methods are also deemed to be acceptable for acceptance testing of commercial shipments.

ASTM B557 Testing Process and Data Collection

The specimen is first prepared as per the respective product form, and its dimensions are measured before testing. The specimen is then placed in the tensile testing machine, and the appropriate extensometer and gripping arrangement are used. As the specimen is loaded in tension, the equipment measures the force applied and the resulting deformation up to the desired test point or until the specimen breaks. The resulting data are then assessed and the applicable tensile properties determined. Finally, engineers document the results of the tensile test and details about the specimen and the test itself.

Common Challenges and Troubleshooting

The accuracy of the results obtained from ASTM B557 will depend upon proper preparation of the specimen, accurate measurement of dimensions, proper alignment, and proper operation of the testing machine. Therefore, it is important that technicians carefully machine samples to prevent surface defects or dimensional errors. Also, operators should check the grips, extensometer, and alignment prior to the test. Lastly, analysts should check the load and deformation data for any unusual results or premature specimen failure.

• The laboratory records the applied load and deformation during tensile loading to establish the material response.
• The analyst checks the maximum load and the applicable dimensions of the specimen to determine the tensile strength.
• The laboratory reports yield strength (in ksi) based on the appropriate yield-strength procedure.
• Engineers evaluate elongation and reduction of area when these properties are required for the applicable product.
• Analysts use the resulting tensile properties to support material comparison, alloy development, quality control, design, and acceptance testing.

Link to ASTM B557