What are the differences between Izod test and Charpy test?

In the Charpy impact test, the sample lies flat on the test bed as a simple beam. Both ends of the specimen get secured before the moment of impact. In the Izod impact test, the sample is in a vertical cantilevered position. Only the bottom end of the specimen gets locked in place.

What is the strain rate of a Charpy impact test?

A fundamental issue in comparing measured dynamic tensile properties and Charpy-based estimations is establishing the equivalent uniaxial strain rate for an instrumented Charpy test, typically conducted at ≈ 5.5 m/s.

How the impact strength is calculated in Izod and Charpy tests?

Impact strength is calculated by dividing impact energy in J (or ft-lb) by the thickness of the specimen. The test result is typically the average of 5 specimens. ISO impact strength is expressed in kJ/m2. Impact strength is calculated by dividing impact energy in J by the area under the notch.

What are the major advantages of Charpy test over Izod test?

Advantages of Charpy Test Cost effective test method for composites. Relatively easy to perform. Helps to assess quality of a product. Useful for evaluating new products.

How do you convert Izod to Charpy?

Multiply the Izod value by 2.738223. Record your new value. This is the Charpy value obtained by multiplying Izod by the Charpy constant.

What is high impact strength?

Impact strength – also called impact toughness – is the amount of energy that a material can withstand when the said load is suddenly applied to it. It may also be defined as the threshold of force per unit area before the material undergoes fracture [1].

How does V-notch differ from U notch?

The basic types of notches are the “V” notch, keyhole notch and “U” notch (Fig. 1). The V-shaped notch is 2 mm deep, with 45° included angle and 0.25-mm radius at its root. The U-shaped notch is 5 mm deep with vertical sides and a 1-mm radius U-shaped root.

What is the size of specimen is used for Izod impact test?

1.2. The Izod impact test is like the Charpy impact test and is used to test materials at low temperature: http://www.wmtr.com/en.izod.html. In this test, a specimen is machined to a square or round section, with either one, two, or three notches that have a dimension of 70 mm × 15 mm × 3 mm [8].

Is Izod number a true measure of toughness?

In reality, Izod measures the notch sensitivity rather than being a true impact measurement. The notch acts as a stress concentrator and simulates what occurs if a part is scratched or cut in a specific application, making it easier to break the product.

What is the difference between toughness and hardness?

Toughness is a bulk property whereas hardness is a surface property. Hardness is related to scratches, abrasion and erosion whereas toughness is related to fracture, compression strength or elongation strength. A tough material can be hard as well but its not true the other way round.

What is the impact energy in case of Izod test?

What is Impact Energy. Impact energy is a measure of the work done to fracture a test specimen. When the striker impacts the specimen, the specimen will absorb energy until it yields. At this point, the specimen will begin to undergo plastic deformation at the notch.