CET 345W Materials Testing Laboratory Experiment No. 4 Impact Test

1. Summary This test is aim to teach students how to do an impact test. The test should give the resistance of any particular notched metallic specimen to fracture under particular type of blow. To do the experiment, the students will be used to measure the amount of energy is stored on a material during facture. The specimen used in the experiment which will include a notched metallic bar. The students will do the most common impact test for metallic materials which is called the Charpy. The experiment will require two types of Charpies. One type of the Charpies will be hot and the other type will be cold. It employs the pendulum principle. During the test, you will see the swing of the pendulum. As a result, the small notched specimens will be broken during the flexure. The notch on the specimen must face away from the striking edge of the pendulum. . A notch shows imperfection in the system, and initiate failure at a location. The potential energy is found when the pendulum in the starting stationary position. When the pendulum is released, the energy will be converted to kinetic energy. To find the highest kinetic energy, it will at the highest point which is at the bottom of the swing. The test will show students how brittle or ductile the two different types of specimens. The results of the test will show a clean cut through the cross section. The ductile failure will show elongated fibers. The test determines material toughness or its ability to resist impact loading. Results indicate differences in the condition of a metal. .......................................................................................CONTINUED