The Vickers hardness test is used for measuring hardness of very hard and very thin materials.

It uses a diamond pyramid indenter and produces a square-shaped indentation.

Definition

Vickers Hardness Test

A hardness test in which a diamond pyramid indenter is pressed into the material surface, and hardness is determined from the diagonal length of the indentation.

Core Concept Explanation

Procedure:

1. Diamond pyramid indenter is pressed onto the material surface.

2. A specified load is applied.

3. The indenter creates a square-shaped indentation.

4. The two diagonals of the indentation are measured using a microscope.

5. Hardness is calculated using the Vickers hardness formula.

Vickers Hardness Formula

HV = \frac{1.854 P}{d^2}

Where:

• $P$ = Applied load

• $d$ = Average diagonal length of indentation

Characteristics

• Uses diamond pyramid indenter

• Produces square indentation

• Suitable for thin materials

• Very accurate hardness measurement

Applications in Engineering

Used for testing:

• Hardened steels

• Thin sheets

• Surface coatings

• Microstructure hardness

Common in research laboratories and precision engineering.

Exam-Focused Points

Important for JE/AE exams:

• Indenter used → diamond pyramid

• Indentation shape → square

• Hardness unit → HV

• Suitable for very hard materials and thin sections

Common Exam Traps

Confusion

Students confuse indenters used in hardness tests.

Correct concept:

• Brinell → ball indenter

• Rockwell → ball or diamond cone

• Vickers → diamond pyramid

Example Competitive Exam Questions

Question: Which indenter is used in the Vickers hardness test?
Answer: Diamond pyramid indenter.

Question: What is the shape of indentation in the Vickers test?
Answer: Square indentation.

Question: Which hardness test is suitable for thin materials?
Answer: Vickers hardness test.

Quick Revision Summary

• Vickers test uses diamond pyramid indenter.

• Hardness based on diagonal length of indentation.

• Produces square indentation.

• Hardness value expressed as HV.

• Suitable for thin and very hard materials.