Quick Guide

Indentation Testing
     Hardness
     Elastic Modulus
     Creep
     Fracture Toughness

Scratch Testing
     Adhesion
     Scratch Resistance

Wear
     Pin-on-Disk
     Linear Reciprocating

Coefficient of Friction
     Static
     Dynamic
     Dynamic with wear

Mechanical Testing
     Tensile
     Compression
     Flexural
     Shear

Profilometry
     Data Processing
     Service

Ellipsometry

Training & Consulting

Surface cracking

Hard coating delamination

Soft coating delamination

We perform our scratch & adhesion tests using the stylus scratch method.  In this method, an indenter is drawn across the sample's surface at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance.



The test parameters are the speed, the loading rate, the scratch length and the indenter used.  Test outputs include the tangential and frictional forces, the penetration and residual depths, the loads at which damages/failures occur and, of course, pictures.  Failures such as cracking, chipping, coating lift, partial and complete delamination can be identified.  The penetration and residual depths provide valuable information about the elastic and plastic deformation.

While the scratch test is computer controlled, at EP Laboratories, we always meticulously identify the critical loads visually under the microscope after each scratch.  It is more time consuming, however it is undoubtedly more precise and accurate.  Some failures, such as cracking and coating lift, can be missed if one only relies on analyzing the output curves.

The scratch stylus technique allows to test the sample "as is"; we believe that it is a more realistic technique than others currently used, such as the peel test, that alter the sample.  Applying a tape, a pressure or making incisions can damage the coating and the interface by creating micro cracks.