The ASM Metals Handbook defines hardness as “Resistance of metal to plastic deformation, usually by indentation” (asmmaterials.info). Therefore, when a compressive force is administered to a solid matter, we can measure how resistant it is to permanently changing shape.
Why is this important?
- A fracture mechanics engineer may consider hard material as brittle and unreliable under impact loads.
- A material scientist, who is concerned with friction and wear, wants high hardness to reduce deformation and wear in bearing applications.
- A mill metallurgist wants a low hardness to make cold rolling easier.
- A fabricator prefers less hard materials for easy and faster machining and to save their tooling.
One definition of material toughness is its resistance to fracture when stressed or ability to absorb energy and deform without fracture.
Why is this important?
Impact testing is a tool to study temperature dependent ductile to brittle transition. Impact testing will show how the material will react when there is a crack initiation zone, as well as how the material will resist sudden or intense fracture.
At Corrosion Materials, we offer a variety of testing services including bend, tensile, corrosion and x-ray testing to uncompromising specifications such as ANSI, ASTM, and ASME.