Wear Tests

Since Systec SVS offers a wide range of wear resistant coatings, it is important to evaluate their ability to resist wear.

Two different devices are used for this purpose:

Calomax NT by made
Fraunhofer IST is a device for standardized wear test allowing for easy comparison of the abrasive wear rate of various coatings. The test evaluates the wear volume of the crater which is formed by the sphere rotating in presence of a special abrasive medium;

all-on-disk wear test, performed at the CSM TRB Tribometer. In this test, the friction occurs between stationary ball and rotating coated sample. The device allows varying the Hertzian pressure, length of wear, wear medium and other parameters. The wear is measured by evaluating the depth, width and/volume of the wear track produced during the test. The test conditions can vary depending on the purpose of the test.

Coefficient of Friction Measurement

CSM TRB Tribometer is used for accurate measurement of friction forces between two bodies. Systec SVS amorphous carbon tribological coatings undergo extensive testing to assure for optimization of friction for various applications. Typically ball-on-disk setup is used for evaluating of friction; however reciprocating mode is also possible. The tests establish the maximum, minimum and average coefficient of friction over the duration of the test. The device also allows plotting the friction coefficient vs. the time of the test.

SEM microscopy and EDX elemental analysis

For the fine characterization of surfaces, fractures and cross-sections, Systec SVS uses SEM microscopy, carried out on Carl Zeiss Gemini microscope. This analysis allows obtaining images of coatings and substrates at the magnifications of up to x 20,000, which provides detailed information about coatings and interfaces. The SEM is also equipped with the EDX (Energy Dispersive X-Ray Spectroscopy) attachment, therefore chemical composition of the coatings and bulk materials can be easily determined as well as elemental mapping.

Scratch Adhesion Measurement

Accurate measurement of coating adhesion is cornerstone for providing essential information about the quality of the coating. This property is equally important for the routine quality checks and development of new films. The adhesion of the coating also reflects its ability to consistently withstand static and dynamic contact loads, usually referred to as load carrying capacity. This property is extremely important for applications where loads are applied in cyclical mode, i.e. many applications in the automotive industry. The scratch method of adhesion evaluation is based on the progressive loading concurrent with lateral movement of the diamond indenter against into the surface of the coated sample. Combination of elastic and plastic deformation of the base material leads to eventual cracking and flaking of the coating. By registering the loads at which these events occur, it is possible to establish so-called critical loads, which uniquely characterize the strength of the interface between the coating and the substrate. In addition to the scratch method, Systec SVS employs adhesion evaluation with the use of Rockwell indentation in accordance with DIN 50103.

Profilometry and Colour Measurement

Another important parameter for friction pairs is surface roughness, which greatly impacts the performance. For its characterization and quality control Systec SVS utilizes SUPTRONIC profilometer by Taylor Hobson, allowing measurement of all major roughness values.

Systec SVS also has the capability to quantify the colours of coatings and substrates. Minolta CM spectrophotometer is used for this purpose. The measurement of colours is important when coluor is one of the functional properties of the coating, or when there is a correlation between the colour and other property of the coating, which is more difficult to measure than colour (for example nanohardness).

Coating Thickness MeasurementThickness

SYstec SVS utilizes two methods of thickness measurement. The mechanical method (Calo Test) involves producing a spherical crater, which extends through the coating into the substrate. By measuring the diameter of the crater and knowing the sphere diameter, coating thickness can be calculated. This method is especially valuable for coatings consisting of several layers. For a majority of ceramic coatings (based on Ti, Cr, TiAl, Zr) x-ray fluorescence method is used, which provides quick and accurate measurement of the coating thickness.