Table of Contents
- 1 How is an Izod test carried out?
- 2 What is the basic objective of Izod test?
- 3 Where are impact tests required?
- 4 Why is Izod test required?
- 5 What is the minimum thickness of impact test?
- 6 How does the Izod impact test work and how does it work?
- 7 How is an Izod test performed on a pendulum?
- 8 Why do Izod specimens have to be notched?
How is an Izod test carried out?
The Izod impact test consists of a pendulum with a determined weight at the end of its arm swinging down and striking the specimen while it is held securely in a vertical position [11].
What is the basic objective of Izod test?
The Izod test is most commonly used to evaluate the relative toughness or impact toughness of materials and as such is often used in quality control applications where it is a fast and economical test. It is used more as a comparative test rather than a definitive test.
What is the angle of notch in the Izod test specimen?
Notch angle for Izod test is = 45°. In solids which show a ductile transition the operative stress system is an important parameter which controls failure. Inclining the notch in a Izod testpiece at 45° to the side faces changes the stress state in the nearby area of the notch from plane strain to plane stress.
Where are impact tests required?
The governing thickness at any welded joint exceeds 4 in. and the minimum design metal temperature is colder than 50°C, impact tested material shall be used. If the governing thickness of non-welded part exceeds 6 in. and the minimum design metal temperature is cooler than 50°C, impact tested material shall be used.
Why is Izod test required?
Brittle materials have low toughness as a result of the small amount of plastic deformation they can endure at any rate. However, ductile materials may behave like brittle materials under high-energy impact, hence the need for this kind of test.
How is Izod specimen supported?
It is supported in the starting position by a catch and can be released by a trigger. The mechanism is so designed that the pendulum is not disturbed when the catch is released. Impact strengths are generally lower as compared to strengths achieved under slowly applied loads.
What is the minimum thickness of impact test?
Full size impact specimens are 10mm x 10mm x 25mm. The minimum controlling thickness for a Charpy V notch specimen is the 10mm thickness by 55mm long.
How does the Izod impact test work and how does it work?
How the Izod Impact Test Works The Izod impact test fixes one end of a notched specimen in a cantilever position by means of a vice. A striker on the arm of a pendulum or similar energy carrier then strikes the specimen. The energy absorbed by the specimen in the breaking process is known as the breaking energy.
Is there an alternative to the Izod test?
An alternative to the Izod test is the Charpy test in which a sample supported, but not gripped, at each end is subject to an impact in the centre. According to the test a notch may be present in the centre of the sample on the face opposite to that subjected to impact.
How is an Izod test performed on a pendulum?
Izod tests are often performed on an instrumented machine with a weighted pendulum. The machine’s operator lifts this pendulum at a certain height and locks it in place. A notched specimen then gets secured on a support anvil in the lower part of the machine.
Why do Izod specimens have to be notched?
Izod impact is defined as the kinetic energy needed to initiate fracture and continue the fracture until the specimen is broken. Izod specimens are notched to prevent deformation of the specimen upon impact.