What is Bainite Microstructure? Bainite is a mixed microstructure in steel that forms at intermediate temperatures between high-temperature pearlite and low-temperature martensite. It's mainly made up of supersaturated ferrite and carbides or carbon-rich retained austenite. Traditional metallography ... Read More

Cold mounting requires no pressure and little heat, and is a means of mounting large numbers of specimens more rapidly than by compression mounting. Materials for cold mounting are classified as polyesters, epoxides and acrylics. Polyesters are transparent and usually water clear; Epoxides are ... Read More

The durometer selection guide cited from ASTM D2240 is designed to assist in the selection of the proper durometer type for various applications. It is generally recognized that durometer hardness determination below 20 and above 90 are unreliable. It is recommended that the next lower or higher ... Read More

Polishing discs are covered with soft cloth impregnated with abrasive diamond particles and an oily lubricant or water lubricant. Particles of two different grades are used: a coarser polish - typically with diamond particles 6 microns in diameter which should remove the scratches produced from the ... Read More

Surface layers damaged by cutting must be removed by grinding. Mounted specimens are ground with rotating discs of abrasive paper, for example wet silicon carbide paper. The coarseness of the paper is indicated by a number: the number of grains of silicon carbide per square inch. So, for example, ... Read More

Principle of the Rockwell Test The Rockwell principle is described as follows: An accurately shaped indenter is used to make an indent in the sample to be tested. This indenter is either a spheroconical diamond, a 120-degree cone with a 0.2 millimeter radius tip, or hard metal ball with a 1⁄16, 1⁄8, ... Read More

Mounting of specimens is usually necessary to allow them to be handled easily. It also minimizes the amount of damage likely to be caused to the specimen itself. The mounting material used should not influence the specimen as a result of chemical reaction or mechanical stresses. It should adhere ... Read More

When cutting a specimen from a larger piece of material, care must be taken to ensure that it is representative of the features found in the larger sample, or that it contains all the information required to investigate a feature of interest. One problem is that preparation of the specimen may ... Read More

What is Cryptocrystalline Martensite? Cryptocrystalline martensite is a microstructural morphology of martensite. Its main feature is that, when observed under a metallographic microscope, there are no obvious needle-like or bamboo-leaf shapes, but rather a blurry, darker-colored area that seems to ... Read More

What is Eddy Current Technique? The most common use of eddy current measurement is for non-conductive coatings over non-ferrous metals such as anodize or paint over aluminum. This technique allows for an accurate reading with even very thin materials through elimination of the base effect. How eddy ... Read More