IMPACT TEST

Significance of Impact test:

            An impact test signifies the toughness of material i.e., ability of material, to absorb energy during plastic deformation. Static tension tests of unnotched specimens do not always reveal the susceptibility of a metal to brittle fracture. This important factor is determined by impact test. Toughness takes into account both the strength and ductility of the material.

           Several engineering materials have to withstand impact or suddenly applied load while in service. Impact strength are generally lower as compared to strength achieved under slowly applied load. Of all kinds of impact tests, the notched bar tests are most extensively used.

Impact tests:

             A pendulum type impact testing machine is generally used for conducting notched bar impact tests. The following type of impact tests are performed on these machines.

    

                  1) IZOD Impact Test                            2) CHARPY Impact Test

DESTRUCTIVE TESTS (MECHANICAL TESTS)

             As the name suggests, Destructive testing (DT) includes methods where your material is broken down in order to determine mechanical properties, such as Strength, Toughness and Hardness. In practice it means, for example, finding out if the quality of a weld is good enough to withstand extreme pressure or to verify the properties of a material.

              The following important mechanical tests give valuable information about metals and alloys as given below:

1	Tensile test	tensile strength, yield strength, elastic limit, young’s modulus, Ductility, toughness etc
2	Impact test	toughness of a material under shock loading condition.
3	Hardness test	wear resistance, indentation resistance, scratch resistance or cutting ability  of material.
4	Fatigue test	Behavior of a material under repeatedly applied stress and its endurance limit.
5	Creep test	Behavior of a material under a steady load over a long period of time and creep limit of a material.