Also called the microhardness method, the Vickers hardness tester is mostly used for thin sections, case depth work, or small parts. It was developed by George E. Sandland and Robert L. Smith in 1921 during their work at Vickers Ltd and is based on an optical measurement system.
The Vickers hardness tester specifies a wide range of light loads using an indenter to make indentation which is measured and then converted to a hardness value. It can be used to test the hardness of almost any type of material (composites, ceramics metals) but test samples must be considered good to enable measuring the size of the impression.
The unit of hardness given by this test is called DPH (Diamond Pyramid Hardness) or HV (Vickers Pyramid Number).
Advantages of the Vickers method
• The measuring range is wide. The Vickers methods can be used to test both hard and soft materials.
• The technique is ideal for laboratory tests.
• The same indenter, a pyramidal diamond, can be used to measure all materials, irrespective of hardness.
• The needed calculations are independent of the size of the indenter.
• The method is extremely easy to perform.
Disadvantages of the Vickers method
• It is a time-consuming process since the print on the surface is measured optically.
• The surface of the sample has to be highly polished.
Despite its weaknesses, the Vickers method is one of the more reliable hardness testing procedures to date. Its ease of maintenance and wide scope of the application make the test a viable addition to any testing workshop or facility.