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Description
The mechanical response of a small volume of material near the surface of a sample is studied by probing the surface
with a diamond indenter of known geometry. A piezoelectric transducer drives the indenter into the sample surface while
load, depth of penetration, and displacement data are continuously collected.
Equipment
The micromechanical tester was designed and built at IBM San Jose.
Diamond indenters:
- Vickers (square pyramid)
- Knoop (elongated square pyramid)
- Berkovich (triangular pyramid)
- right circular cones with tip radii of 1, 5, 10, and 50 µm
Semi-automated PC interface to control the machine and collect data.
Accessories:
- Hot stage: fixed temperatures from ambient to 100 °C
- Tangential load cell for measuring lateral forces
Applications:
The instrument may be used to characterize the mechanical properties and
adhesion strength of films. Indentation, microscratch, load relaxation,
indentation fatigue, indentation creep, and dynamic mechanical experiments
can be performed on coatings to obtain information on hardness, elastic
modulus, storage and loss moduli, friction coefficients, film adhesion, and
fracture toughness. 3 and 4 point bending, tensile, compression, crush,
peel and fiber pushout tests can also be performed.
Scratch tests are performed by drawing the indenter across the surface as it
penetrates. Delamination of films allows qualitative and, in some cases,
quantitative evaluation of interfacial properties.
Virtually any test that requires pushing or pulling under carefully controlled
conditions within the physical limits of the equipment can be performed.
Materials and coatings of all kinds from highly viscous polymers to
diamond-like carbon have been studied.
Capabilities:
- Maximum Sample size: Specimens 2 cm high and 5 cm across. Larger
samples can be accommodated with some geometrical constraints. A
smooth surface produces best results.
- Load resolution: 50 µN
- Depth resolution: 5 nm
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