Understanding what the numbers mean and how they relate to material properties is required to interpret Vickers hardness test results. Here's a breakdown to help you:

Understanding the Format

l HV: The Vickers hardness scale is indicated.

l Hardness Number: This is a numerical value that represents the material's hardness. Greater hardness is indicated by higher numbers.

l Load (kgf): This is the test load used during the measurement. Micro-Vickers tests typically range from 10gf to 1kgf, while macro-Vickers tests range from 5kgf to 30kgf.

Interpreting the Hardness Number

l Comparison with reference values: Check to see if your material type has established hardness ranges. This allows you to see how your sample compares.

l Relative comparison within the sample: Hardness can be compared across different areas of the same sample or between samples under similar conditions.

l Consider the load: Due to material deformation, higher loads can result in slightly lower hardness values. The values, however, generally stabilize above 200gf.

Additional Factors

l Material microstructure: The grain size, phase presence, and phase distribution can all affect hardness.

l Test conditions: Ensure proper preparation, testing procedure, and calibration of equipment.

l Reporting format: Additional information, such as indentation size or conversion to other hardness scales, may be included in some reports.