Impact Testing

Impact testing is a valuable method to determine the amount of energy a material absorbs during fracture. Useful on both metals and polymers, IMR offers several impact test methods, including:

  • Charpy Impact Testing (metals only)
  • IZOD Impact Testing (nonmetallics only)
  • Gardner Impact Testing (nonmetallics only)

Charpy Impact Testing

Charpy impact testing is a valuable method to determine the amount of energy a material absorbs during fracture. Also known as a Charpy V-Notch test,  a pendulum is dropped from a known height and impacts a notched specimen of material. By comparing the difference in the height of the hammer before and after the fracture, one can measure the energy absorbed.

This provides information on the material's notch toughness and helps understand temperature-dependent ductile-brittle transition.  Ductile vs. brittle fracture can be compared by looking at the flat planes (brittle) and the jagged edges (ductile) to estimate a percentage of each.

IMR Test Labs offers Charpy impact testing to several specifications and at temperatures from -320F to 400F.  

Specifications Offered:

  • ASTM A370
  • ASTM E23
  • ISO 148-1
  • JIS Z 2242

IZOD Impact strength Testing

IMR Test Labs in Ithaca, NY offers IZOD impact testing on polymeric materials.  

Similar to Charpy impact testing, a known weight on a pendulum with a striker is released from above the specimen.  The pendulum strikes the specimen, and the energy absorbed by the specimen is displayed. 

This test differs from Charpy impact testing in that the sample is held in a cantilevered beam configuration instead of a three point bend configuration.  Izod testing is used mostly for polymer and composite materials.

IMR Test Labs in NY is accredited to test to method ASTM D256.

Gardner Impact Testing

Best for determining the strength of a coating, Gardner impact testing does not use a pendulum, but instead a column with a weight at the top and an impactor that sits on top of the sample.

Specimens are placed under the striker, and a weight is dropped from a known height, impacting the specimen with a known energy. 

IMR has several weights and scales to accommodate a wide range of specimens.  IMR's lab in New York is accredited for methods ASTM D2794 and ASTM D5420.