Introduction
A Micro-Vickers Hardness Tester is widely deployed for material hardness characterization thanks to its broad test-force coverage. Practically all workpieces meeting surface roughness requirements can undergo hardness evaluation with this Vickers hardness testing instrument. Precision micro-hardness testing for thin layers and small-size components is critical for metallurgical labs and quality-control departments. The instrument drives indentation onto sample surfaces via stepper motor actuation, then measures diagonal dimensions of indentations through reading optics to calculate Vickers hardness values by mathematical conversion. Lab users may consider well-engineered models such as Mikrosize uVK-1 when sourcing a reliable material hardness measurement unit for multi-purpose hardness analysis.
Working Principle of Vickers Hardness Test
Vickers hardness value equals test force divided by the surface area of the indentation. Formula:
HV = Constant × Test Force / Indentation Surface Area ≈ 0.1891 F / d²
Where:
- HV = Vickers hardness symbol
- F = applied test force (Unit: N)
- d = arithmetic mean value of two indentation diagonals d1 and d2 (Unit: mm)
Operators can look up corresponding Vickers hardness values according to measured diagonal length d. Per standard specifications, diagonal length of Vickers indentation shall range between 0.020 mm and 1.400 mm.
Classification of Vickers Hardness Tests
Based on magnitude of applied test force, Vickers hardness tests fall into three categories:
- Vickers Hardness Test
- Low-Load Vickers Hardness Test
- Micro-Vickers Hardness Test
Selection of test force shall be determined by specimen type, sample thickness and expected hardness range. Relevant standards specify that specimen thickness or test layer thickness must be at least 1.5 times the length of indentation diagonal. A qualified Micro-Vickers Hardness Tester should cover the necessary range of test forces to satisfy these three test categories.
Representation of Vickers Hardness Values
Vickers hardness results are marked with symbol HV. The numeral ahead of HV stands for hardness value, followed by the value of applied test force. Standard dwell time is 10 15 seconds. For non ferrous metals, dwell time shall not be shorter than 30 seconds. If dwell time deviates from standard range, actual holding duration shall be annotated behind force value.
Examples:
- 300HV30 — Hardness value 300 obtained under 294.2 N (30 kgf) test force with 10-15 s dwell time.
- 450HV30/25 — Hardness value 450 obtained under 294.2 N (30 kgf) test force with dwell time extended to 25 seconds.
Applications of Vickers Hardness Test
Vickers hardness testing serves material-science research and laboratory experiments. Low-load Vickers hardness tests are suitable for small precision components, surface hardened-layer hardness & case-depth measurement, plating surface hardness, thin sheets and fine wires, as well as hardness inspection near cutting edges and dental materials. Owing to minor indent size, original appearance and service performance of tested workpieces remain intact.
Precision micro-hardness testing for thin layers and small-size components is accomplished by Micro-Vickers hardness tests. They are widely used within metallurgy and material science research, for hardness measurement of individual constituent phases inside metallic microstructures and brittleness evaluation of refractory compounds. Micro-Vickers hardness test can handle ultra-thin or miniature parts with sample thickness down to 3 μm. A capable Vickers hardness testing instrument shall support multi-objective lens combinations to deliver reliable measurement for thin plating, surface modification layers and tiny samples common in industrial QC labs.
Advantages of Vickers Hardness Test
Vickers hardness test is well-suited for hardness measurement of thin samples. A square-based diamond pyramid indenter penetrates sample surface under defined test-force; after specified dwell duration, force is unloaded and indentation diagonals are measured. Indentations generated are square-shaped with sharp clear outlines for precise diagonal reading. Therefore, Vickers hardness test provides outstanding repeatability compared with Brinell hardness test.
It covers an extremely broad hardness scope, measuring nearly all industrial metallic materials from very soft grades (several HV units) up to extremely hard alloys (3000 HV).
A core merit: resultant hardness value is independent of applied test-force magnitude for homogeneous materials. Identical hardness readings can be obtained with different force settings, forming a unified hardness scale across wide ranges — this represents a major advantage over Rockwell hardness testing. Within medium-to-low hardness intervals, Vickers test outputs approximate values compared with Brinell hardness on uniform material. Test force can go as low as 10 gf, generating tiny indentations ideal for ultra-thin and miniature specimens. Many modern material hardness measurement unit models are equipped with built-in hardness-conversion function to convert HV values to HRA, HRB, HRC, HBW and other hardness scales directly on-device.
Disadvantages of Vickers Hardness Test
Vickers hardness testing has relatively low testing throughput. It imposes high requirements on surface finish of test specimens; samples normally demand careful pre-preparation. Overall operating workflow is time-consuming, so it is mostly deployed in laboratory environments.
Conclusion
As a versatile Micro-Vickers Hardness Tester, the Vickers hardness testing instrument delivers unique strengths for thin-wall parts, surface layers and material-science research despite its limitations on testing efficiency. Lab operators must select appropriate test force strictly complying with standards, guarantee sufficient sample thickness and meet surface-preparation requirements to acquire credible hardness data.
Such Vickers hardness testing instrument finds extensive adoption across metal-processing workshops, heat-treatment laboratories, aerospace component inspection, electronic material research and dental material evaluation.
For laboratories looking for complete-featured hardware, Mikrosize uVK-1 Micro Vickers and Knoop Hardness Tester is one viable option. It features auto-turret for Vickers & Knoop indenters, dual-optical-path design, adjustable LED cold-light source, touch-screen operation, data export and printing functions. It conforms to GB/T4340.2, GB/T18449.2 and ASTM E92 for standardized micro-hardness testing. Mikrosize delivers one-stop testing solutions covering instruments, certified accessories, operational training and technical calibration support. Beyond hardness testers, our product portfolio extends across the full workflow of material analysis. We work closely with industrial and research laboratories worldwide to match suitable hardware and services for diverse material-testing requirements.
