ASTM E92
Full Name
ASTM E92 – Standard Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials
Scope
ASTM E92 is a standard test method used to determine the Vickers and Knoop hardness of metallic materials. These hardness tests are based on the principle of indentation, where a diamond indenter is pressed into the material’s surface and the resulting indentation is measured.
Vickers hardness:
- Indenter: square-based pyramid diamond indenter.
- Load: typically 1, 5, 10, 25, 50, or 100 kgf.
- Measurement: diagonals of the indentation are measured using a microscope.
- Calculation: Vickers hardness number (VHN) is calculated based on the applied load and the average diagonal length of the indentation.
Knoop hardness:
- Indenter: diamond indenter with a rhombohedral shape.
- Load: typically 1, 3, 5, 10, 25, or 50 kgf.
- Measurement: length of the long diagonal of the indentation is measured using a microscope.
- Calculation: Knoop hardness number (KHN) is calculated based on the applied load and the length of the long diagonal of the indentation.
Applications – both Vickers and Knoop hardness tests are widely used in various industries, including:
- Manufacturing: quality control, materials selection, and process monitoring.
- Research and development: material characterization and performance evaluation.
- Construction: inspection of structural components and materials.
Resources
Keywords
Vickers hardness; Knoop hardness; metallic materials; test method; indentation; diamond indenter; load; measurement; calculation; VHN; KHN; quality control; material selection; process monitoring; research and development; manufacturing; construction; inspection; structural components; materials; surface preparation; defects; strain hardening; grain size; heat treatment; material composition; factors affecting Vickers and Knoop hardness; applications; testing services; ASTM E92