Material toughness is studied via impact testing. Toughness measures a material’s capacity to absorb energy during plastic deformation. Brittle materials have low toughness due to the limited amount of plastic deformation they can withstand.
Temperature can also affect a material’s impact value. In general, with decreasing temperatures, a material’s impact energy decreases. The size of the specimen may also influence the result of the impact test since it allows for a varying amount of flaws in the material, which can function as stress risers and reduce impact energy.
Charpy and IZOD Specimen arrangements are the most widely used in impact testing.
The Charpy Impact Test is a standardised high strain rate test that assesses how much energy a material absorbs during impact. The absorbed energy of a material is a measure of its notch toughness. It is frequently used in industry since it is simple to set up and carry out, and results can be acquired fast and cheaply.
Performed on instrumented devices that measure less than one joule (J) to 750 joule (J) and the temperatures range from -180°C to over 300°C. Impact test specimen types include notch configurations such as:
The Izod impact strength test is an ASTM standard measuring material impact resistance. A pivoting arm is lifted to a specified height and released (constant potential energy). The arm swings down, striking a notched sample and shattering it. The energy absorbed is estimated by measuring the height to which the arm swings after striking the sample. A notched sample is often utilised to calculate impact energy and notch sensitivity.
The test is comparable to the Charpy impact test, but the specimen under the test is arranged differently.
E.g., The sample in the Izod impact test is held in a cantilevered beam arrangement rather than a three-point bending configuration, which distinguishes it from the Charpy impact test.
Automatic Impact Testers are motorized pendulum impact testers. They are fully automated, high-performance devices which are ideal for testing metals according to Charpy and Izod standards. But how exactly are robotic testers better than human testers? Let’s look at a few advantages of using Automatic Impact Testers over non-motorized analogue testers.
Although nearly all materials can benefit from impact testing, the most typical types include metals, plastics, wood, composites, ceramics, and polymers. Depending on the test, these materials might take the form of sheets of varied thicknesses or short rods.
However, depending on the type of test, the rate of loading, and the temperature of the sample, most materials will fail as ductile or brittle. Brittle failure of a material necessitates a small amount of energy to initiate or propagate the fracture until the sample collapses. A ductile failure of a material, on the other hand, needs a significantly larger load to originate and propagate the fracture till collapse.
Automatic Impact Testing Machines are available from Blue Star E&E for both metallic and non-metallic materials. Our impact testers are outfitted with cutting-edge software that produces easy to read results compatible with Microsoft Word and Excel. The ultra-low temperature chambers are intended to conduct testing in accordance with ASTM and ISO standards and utilise both compressor and liquid nitrogen cooling. If you require, we also provide sheet punching machines for nonmetals and extremely thin films to meet your specific needs. Our drop weight impact testers are appropriate for drop weight tear testing of different ferrites in accordance with ASTM E436, API RP 5L3, and DIN EN 10274 standards.
Get in touch with Blue Star E&E today for all your material testing needs.