Vickers hardness test
The Vickers hardness test measures the hardness of a workpiece by indenting with a square-based diamond pyramid and measuring the area of the indentation. It is universally applicable for all materials and coating thicknesses.
Physicochemical Mechanism of Action
The Vickers hardness test uses a four-sided diamond pyramid with an 136 degree included angle that is pressed into the workpiece. The indentation force can be variably controlled and causes a plastic strain region in the material. Hardness is determined by the size of the indentation area.
Metallurgical Relevance & Welding Risks
The Vickers hardness test is especially useful for thin-walled workpieces and coating thicknesses where other hardness testing methods like the Brinell test are not suitable. It provides precise measurement of local hardness distribution and can be used to analyze the effects of welding processes on material hardness. Incorrect test conditions can lead to inaccurate results, which in turn can cause false conclusions about material selection or process optimization.
Workshop Practice & Procedures
For the Vickers hardness test, a special microscope with a hardness tester is used. The workpiece is viewed under high magnification, and the indentation force is set to produce a visible pyramid shape. The area of the pyramid is then measured, and hardness is calculated according to a standard procedure. It is important that the workpiece is clean and free of dirt or corrosion to achieve accurate results.