An abrasion tester is a device designed to gradually or quickly erode the surface away from a solid material to determine the life of the material or the durability of the coatings it has. Materials that an abrasion tester is often used on include metals, ceramics, plastic composites, and thin film coatings on cutting tools and bits. Testing of common surface materials such as laminate flooring, paints, varnishes and more can also be the focus of abrasion testing.
There are dozens of different test methodologies and equipment designs for how an abrasion tester functions. Almost all of them voluntarily conform to various levels of technical standardization established by the American Society for Testing and Materials (ASTM), an international organization founded in the year 1898. Testing levels that ASTM guidelines cover range from minor surface testing known as scratch-and-rub testing, to heavier abrasion and wear testing. Crock testing is also an abrasion tester feature, which is based on ASTM standards that simulate the repeated rubbing action of human fingers and forearms on a surface.
There are a number of different types of abrasion tester equipment used to test durability. One option employs a rotating sphere with a dead weight that is placed against a surface. An abrasive sand or diamond slurry is then introduced between the sphere and surface to test coatings for cutting tools. The Crock Meter is another method used to test color transfer from textiles and painted surfaces, or how much the toner in a photocopier image will smear. These devices utilize an acrylic rubbing device shaped like a human finger that rubs back and forth along a surface in a four inch (100 millimeter) range.
The Falling Sand Abrasion Tester is another less frequently used version of these machines. It employs a slow process that works by dropping abrasive particles through a guide tube onto a surface to wear it away. It can take up to 159 gallons (600 liters) of sand particles impacting the surface before wear effects are noticed.
The most common approach to testing abrasion-resistant materials is probably the use of the Dry Sand Rubber Wheel Abrasion Test that conforms to ASTM guideline G-65. This is used to determine scratch abrasion, or low levels of surface degradation, by rotating a rubber wheel against a surface and introducing sand particles between the two. This test is low impact and doesn't alter the shape of the abrasive material used, unlike high stress abrasion testing equipment that results in fracturing of the abrasive particles into smaller pieces as they cut into the surface.
Abrasion testing processes are important as they are key to making strong materials. The more durable a material surface is, the more consumers are willing to pay for it and the better the manufacturing process becomes. Company reputations and trademark recognition are often built around their materials being more durable than those of chief competitors. As well, the inclusion of warranties in product claims is backed up by the standardized testing that abrasion results yield.