A materials test to determine how well a material performs when subjected to a sharp impact is known as an impact test. The goal is to see how well the material performs in real-world situations and to ensure that it complies with any regulatory requirements. Companies that perform materials testing usually offer a variety of impact tests, and if they have the necessary facilities and personnel, they can also conduct their own. One benefit of conducting testing in-house is the ability to protect confidential information.
Objects can be subjected to a variety of impacts in the course of normal use. Dropped, slammed against hard surfaces, or hit by flying projectiles are all possibilities. Whether they crack, pit, or shatter is determined by their ability to absorb impact stress. The overall lifespan of objects in high-impact environments, such as a car engine, is determined by their resistance to impact. It may not be enough for an object to survive a high-pressure impact if it is unable to do so repeatedly.
A precise control of conditions is required during an impact test. A technician can deliver a targeted impact with a known amount of strain using a test machine with carefully calibrated components. An object may be dropped, hit, or subjected to other types of impact, including repetitive strain, by the machine. Materials can be fixed in place to deliver maximum impact to a single location. The material has a notch cut into it in some types of impact tests, and the test involves hitting the notch to see how the material reacts.
Some materials are extremely brittle, and even minor impacts can cause them to fail. Others are ductile, which means they can deform or bend before breaking. They are usually more tolerant of high impacts. However, ductile materials are not always possible to use in construction because the stiffness of brittle materials is sometimes required to meet the needs of a given manufacturing project. Rubber, for example, can be brittle when frozen but ductile at room temperature, so materials scientists must consider how properties change in response to environmental conditions.
An internal lab can usually be used for a basic impact test during product and material development. Before being released on the market, some materials will need to be tested by an independent, verified lab. This may be required by regulators for safety reasons. This, as well as other materials testing, can be used in quality control procedures. Employees can pull and test random samples on a regular basis to ensure that they meet the company’s standards.