Hardness is the resistance of a material to localised plastic deformation. Hardness ranges from super hard materials such as diamond, boron-carbide to other ceramics and hard metals to soft metals and down to plastics and soft tissues. Hardness is just one mechanical measurement and properties such as toughness and strength need to be considered, as hard materials tend to have low toughness and can easily fracture.
Hardness can be assessed by a number of techniques including indentation, scratch and rebound hardness measurements. nCATS has access to standard Vickers hardness and micro-hardness machine, but has instruments to explore hardness at the nano-scale with nanoindentation and indentation with the atomic force microscope.
One of the nanoindentation machines is fitted with a hot stage to explore hardness as a function of temperature, usually referred to as ‘hot hardness’, this is important as the temperature of material increases, hardness decreases and at some point a drastic change in hardness occurs.