6. Hardness testing on brittle materials
Under the load of an indenter, a brittle material can only deform plastically to a very limited extent; it reacts by cracking. Cracks appear at the edges of the indenter. In the case of a ball, the crack takes the shape of a cone - the Hertzian cone crack. In the case of a pyramidal indenter, cracks propagate from the four corners of the indentation. The indenter acts on these cracks by causing them to open under conditions of imposed displacement. As a result, they are stable and propagate only as the penetration depth increases (although this is only true in the absence of environmental effects).
Propagation occurs if the stress intensity factor exceeds the material's toughness K Ic , but stops when the cracks have reached a certain characteristic length. This is because the stress intensity factor decreases as crack...
The Ultimate Scientific and Technical Reference
This article is included in
Friction, wear and lubrication
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Hardness testing on brittle materials
Correspondence between different hardness scales
Bibliography
Standardization
NF EN ISO 6506-1 October 1999
Metallic materials – Brinell hardness test – Part 1: Test method
NF EN ISO 6506-2 October 1999
Metallic materials – Brinell hardness test – Part 2: Verification and calibration of testing machines
NF EN ISO 6506-3 October 1999
Metallic materials – Brinell hardness test...
Manufacturers Suppliers (non-exhaustive list)
Testwell http://www.testwell.fr
Zwick http://www.zwick.fr
SOMECO http://www.someco.fr
Wolpert HCH Reimmann AG machine...
The Ultimate Scientific and Technical Reference
