For tensile testing of Nano Hybrid AL-Alloy-based metal matrix composite (MMC) materials, you can use the ASTM E8 standard, which outlines the procedures for conducting tension tests on metallic materials.

In terms of specimen dimensions, the ASTM E8 standard specifies that the test specimens for tensile testing should be in the form of a round or flat tensile bar, with the width and thickness of the specimen depending on the size and shape of the material being tested. For example, the standard specifies that for materials with a thickness of 1/4 inch (6.35 mm) or less, the width of the specimen should be at least twice the thickness, while for materials with a thickness greater than 1/4 inch, the width of the specimen should be at least 1.5 times the thickness.

It is important to note that the specimen dimensions for tensile testing may vary depending on the specific requirements of the test and the characteristics of the material being tested. It is recommended that you consult the relevant ASTM standard or other appropriate guidelines to determine the appropriate specimen dimensions for your specific application.