What is the difference between IZOD and Charpy Impact tester

What is the difference between IZOD and Charpy Impact tester

In such a blossoming world of material science and engineering, gaining insight into the toughness and resistance to the impact of materials becomes a need. This blog, therefore, shall provide the more popular models that provide great use in measuring the toughness and resistance to the impact of materials. The most commonly used tests for measuring impact strength are the Izod and Charpy tests. While both focus on measuring the energy absorbed through the material under fracture, their techniques, applications, and results vary. This blog intends to provide readers with a perspective on Izod and Charpy tests they should differ in their procedures, relation to the aspects of differences uniqueness, and importance to testing materials.

Izod Test

The Izod is an impact test measuring approximately the energy absorbed by a material within an instant impact energy. It was named after Edwin Gilbert Izod, who devised the test in 1903. It is employed for metals, plastics, and other materials. A notched specimen is struck with a pendulum hammer and the energies absorbed by the specimen at the moment of fracture are recorded.

Key Features of the Izod Test

The key features of the Izod Test where the metals, plastics, and other materials in which the instant impact of energy is measured are herein mentioned below ways for the help you know where this test is to be used. Here are the key features of the Izod Test: 

1. The specimen in the Izod test is mounted vertically with the notch side facing the pendulum.
2. The notch is on the same side as the impact, directing force to that point.
3. The energy absorption is determined based on the height of the polled swing before striking the specimen and after it has fractured.
4. The Izod is generally known to stand for the evaluation of impact strength in plastics and polimer testing instrumnets, especially in the automotive, construction, and manufacturing sectors.

The Charpy Test

The Charpy test was first devised by Georges Charpy in 1901 as another method of impact testing for measuring toughness. Like the Izod test, this is done through a pendulum hammer that strikes a notched specimen. However, there are significant differences in the setup and execution of the test. But distinctly, the tests are set up and different from one another in their execution.

Key Features of The Charpy Test:

Below are the key features of the Charpy Test that are used for testing the toughness of the materials, including metals only. Read the key features below:

1. Specimen Orientation: A test of the Charpy with the specimen horizontally laid on the horizontal supports at both ends pointing a notch away from the pendulum.

2. Notch Position: The notch faces away from the impact point, creating a different stress distribution from that in the Izod test.

3. Energy Measured: In measuring the energy absorbed by the specimen, the pendulum's height difference after impact is measured before impact.

4. Applications: The Charpy test generally spreads the use of metals mainly in construction and aerospace, to assess a material's capacity to withstand an impact.

The key difference between Izod and Charpy test

Though both are tests to assess impact strength, the other differences lie in the methodology followed while conducting the tests, as well as their applications along with the difference between Charpy and Izod impact tests. The following are the main difference between Izod and Charpy tests:

Importance of Izod and Charpy Tester

The Izod and Charpy tests are valuable in measuring and utilizing the toughness and impact resistance of materials. Toughness is a most important property, especially in applications where materials are exposed to sudden loads or impacts, such as:

• In the automotive industry, the impact or sudden load on materials is based on collision and vibration.
• In the construction industry, structural materials load against an environmental impact.
• In aerospace, the potential for such materials to face elemental effects is more striking during aircraft flight.

Engineers and material scientists choose these tests considering all these differences, thus ensuring that they choose the right test for their specific needs, confirming their products' reliability and safety.

Which Test: Izod or Charpy

The selection between Izod and Charpy tests relies entirely on the specific material used for testing and the purpose for which it is to be used. Some guidelines include:

Use Izod for plastics and thin metals since this gives accurate results for these materials.

Use Charpy for metals since, in structural applications, it is suitable for determining the toughness of thicker materials. 

Conclusion

The Izod and Charpy tests are great indicators of the impact strength of a material. While considerably close in numerous respects, the differences between the two methods are; the orientation of the specimen, placement of the notch, and applications. Such differences shall be of assistance to an engineer in selecting the most appropriate test for his needs so that the material may be of good performance and safe in application in industries.

The ability to differentiate between the two types of tests allows materials engineers to make informed decisions regarding plastics, metals, and any other materials that they may work with. So, in the future, if you ever happen to encounter either of these tests, you can impress your audience with your previously acquired knowledge of both tests and their various applications with test your product material testing instruments.