hardness test

Hardness test is the most simple and easy test method in mechanical property test. The hardness value is not only related to the elastic limit, modulus of elasticity, yield limit, brittleness, but also to the crystalline state of the material, the bond strength between atoms and the atomic structure, etc. the hardness measurement is characterized by no damage to the workpiece, convenient operation, rapidity and high efficiency.            Hardness test classification: 1. Dietmar Leeb, 2. Hb, 3. HR, 4. HV, 5. Shore, 6. HW.            The hardness test methods are as follows:            Hydrostatic test & mdash; is used to determine the resistance of materials to permanent deformation. Such as Brinell hardness, Rockwell hardness, Vickers hardness, microhardness.            Scratch test & mdash; to determine the resistance of materials to cracking. Observe whether one material can be scratched by another material, such as martensitic scratch hardness and Mohs scratch hardness.            Plough groove test & mdash; a blunt head element (usually diamond) is scratched across the surface under certain load and similar conditions, and the scratch width is taken as the hardness measurement standard. Such as Bierbaum hardness test.            Rebound test & mdash; or elastic rebound method, to determine the resistance of materials to elastic deformation. Make an object of standard mass and size bounce back from the test surface, and take the bounce height as the hardness standard. Such as shore hardness.            Damping test & mdash; also known as rolling test, to determine the resistance of materials to permanent deformation. Such as rocking hardness.            Wear test & mdash; press the sample on a rotating disc, and take the wear rate as the hardness measurement standard.            Erosion test & mdash; under standard conditions, abrasives are shot on the test surface, and the weight of the material lost in a certain period of time is taken as the hardness measurement standard.