The test requires applying a progressive increasing load on the sample that needs to be tester with a tip. During the process of applying the load the sample is moved at a constant velocity. During the test several parameters such as Friction (Fx), Down force (Fz), Coefficient of friction (COF), displacement (Z), Acoustic emission (AE) are measured insitu. Failure of coating is determined by change in one of several of the measured parameters mentioned above. Typically ASTM standards such as ASTM d7187, C1624, 7025-05, ISO 20502, ISO 1518 mentions monitoring COF to determine point of coating failure . The load range, choice of tip is determined by the coating thickness, application, surface roughness etc.
Scratch hardness is the ability of a material to resist plastic deformation, usually by scratches and abrasion. The scratch module allows to measure scratch hardness and resistance of bulk material. For coating scratch hardness and adhesion please read the coating section. The test requires moving a sharp tip at constant load on the surface that needs to be characterized and on the standard sample with known hardness. During the test several parameters such as Friction (fx), Down force (Fz), Coefficient of friction (COF), displacement (Z), Acoustic emission (AE) etc. are measured insitu. As per ASTM standards G171-03 Hardness of coating is determined by calculating the ratio of width of scratch track between the sample and standard sample. The sample automatically moves under imaging technique of choice (WLI, AFM, microscope) and creates a complete 3D image by stitching across entire track. The width of the track is calculated from this image.
Coating Thickness < 1000nm
Max Down Force 1000mN
Coating Thickness < 5 microns
Max Down Force 50N
Coating Thickness > 5 microns
Max Down Force 200N
The micro hardness module allows to measure traditional hardness (rockwell, vicker, brinell etc.) with ease. The hardness information obtained may correlate to tensile strength, wear resistance, ductility, and other physical characteristics of metallic materials, and may be useful in quality control and selection of materials.
The tests can be done in room temperature or at high temperature (hot hardness) upto 1000C.