Pages: 18 Published: Jan 2007
THE FIRST STATIC HARDNESS TESTING METHOD WAS INTRODUCED BY J. A. Brinell, a Swedish researcher, at the 1900 Paris World Exposition. A hardened steel ball or tungsten carbide ball with a diameter (D) of 1, 2, 2.5, 5, or 10 mm was used as indenter. This was pressed into the smooth, clean specimen surface with a test force (F). Figure 21.1 shows the principle of test with test force F (N), D the diameter of the ball (mm), d the mean diameter of the indentation (mm), and h the depth of the indentation (mm). It is important that the specimen rests on a rigid support, and that the indenter contacts the specimen without being shaken or jolted. The test force is then increased to the predetermined maximum value within 2-10 s and held for 10-15 s. If the duration of load application falls outside of this range, this must be indicated. For example, for nonferrous materials, the duration may be as long as 180 s.
Metallography, Materialography, Preparation methods, Sample preparation, Mechanical polishing, Electrolytic polishing, Cutting, Sectioning, Hot mounting, Cold mounting, Grinding, Polishing, Polishing artifact, Etching, Microscope, Quantitative metallography, Stereology, Vickers hardness, Quality control, Microstructure
Paper ID: MNL11201M