ASTM E23 describes impact testing of notched-bar metallic specimens. The standard covers both Charpy and Izod style testing and outlines test methods for measuring the energy absorded by the broken specimen. Here we will look at Charpy testing on sub-size specimens. A Charpy test requires the notched metal specimen to be held on both ends (in a horizontal fashion) and is broken by an anvil strike at the location of the notch. The diagram (bottom right) illustrates the test set-up for Charpy testing.
For this test we chose a
SI Series Pendulum Impact Tester because it is designed for Charpy testing. Due to material limitations, we were unable to use a standard size Charpy specimen; so, we referred to Annex A3 of ASTM E23 to test a sub-size specimen. To accomodate the smaller Charpy specimen we used different specimen supports. We can supply support blocks to accomodate the following sub-size specimens: 2.5mm x 10mm (part number W-3594), 5mm x 10mm (part number W-3595), and 7.5mm x 10mm (part number W-3596). Supports for special sub-size thicknesses can also be manufactured. With the specimen supports in place, we loaded the smaller Charpy sample and raised the striker in preparation for the test. We used a lever to release the striker and break the specimen. We captured the energy absorbed during the test by reading the dial; alternatively the SI series can be outfitted with a data aquisition unit.
We recommend that you review ASTM E23 to fully understand its requirements. Instructions for testing smaller Charpy samples can be found in Annex A3 of ASTM E23.