CharpyPendelschlagprüfung

The Charpy pendulum impact test, commonly called the Charpy impact test, is a standardized method for measuring the energy absorbed by a material during fracture when struck by a falling pendulum. Created by Georges Charpy in 1905, the test provides a measure of impact toughness useful for comparing alloys, heat treatments, and service-temperature performance. It is widely used for metals and also adapted for some polymers and ceramics under appropriate standards.

In the test, a notched specimen is supported as a simple beam and positioned in the path of a pendulum hammer. The pendulum is released from a known height and strikes the specimen at the notch, causing brittle or ductile fracture depending on material and temperature. The energy absorbed by the specimen is determined from the difference between the pendulum’s initial potential energy and its energy after breaking the specimen, typically reported in joules. Notch geometry, specimen dimensions, and the support span are specified by the relevant standard.

Common variations include Charpy V-notch and Charpy U-notch specimens. Temperature control is often important, with tests performed at ambient and specified lower temperatures to identify the ductile-to-brittle transition temperature. Standards governing the test include ASTM E23 for metallic materials and ISO 148-1, among others, with detailed requirements for geometry, alignment, calibration, and reporting.

Applications focus on assessing impact toughness of steels and other metals, informing material selection, quality control, and heat-treatment decisions. Limitations include sensitivity to specimen preparation, notch quality, temperature, and test setup, so results are most meaningful when comparison follows identical conditions.