Notched Bar Impact Testing of Metals
ASTM E23 outlines standards for impact testing using both the Charpy and Izod methods. A hammer pendulum swings down to strike a notched bar sample. The measurement in Joules is taken from the amount of energy that is lost from the swinging hammer striking the specimen. This lost energy is measured and taken as the Absorbed energy value ( J ).
Sample specimens are usually 10x10x55mm. There are several styles of notches which can be cut out of the sample using either a manual or automatic broaching machine. The most common is Type A which is a 45 degree notch cut out of the center of the sample at a 2mm inset.
Impact Testing Machines are relatively simple to specify with the main option being whether to choose the Charpy (Simple-Beam) method or the Izod (Cantilever-Beam) method. Either method uses a slightly different hammer which is interchangeable except for the extremely large hammers. Anything over 300 joules requires a dedicated hammer on the machine since it is too heavy to interchange.
The Galdabini integrated user interface makes the operation and data analysis simple and safe. Using a touchpad the technician can control the machine and collect data.
1. Absorbed energy (Joules).
2. Residual energy (Joules/cm^2). (aka Resilience value)
These two values can be stored on non-volatile memory and then exported to a PC via a USB connection. Further analysis can then be performed on the data using Excel or a Laboratory Information Management System (LIMS).
ASTM D6110 - Notched Impact Testing (Plastics)
ASTM D256 - Unnotched Izod Impact Testing (Metal)
ASTM D4812 - Unnotched Izod Impact Testing (Plastics)
ASTM E2248 - Miniaturized Charpy V-Notch Specimen Testing