Nanometer coating measurement

Despite the recent detrimental report on carbon nanotubes and issues like consumer scepticism and nano waste, new nanotechnology consumer products are coming on the market at the rate of three to four per week; a finding based on the latest update to the Nanotechnology Consumer Product Inventory maintained by the Project on Emerging Nanotechnologies (PEN).

The number of consumer products using nanotechnology has grown from 212 to 609 since PEN launched the world's first online inventory of manufacturer-identified nanotech goods in March 2006. Experts estimate that - by the year 2014 - about 15 percent of the total global output, will be made with at least some nanotechnology.

Early products have been in food, electronics, health care, clothing and cars; like this typical example:

There are 35 automotive products in the PEN inventory, including the Hummer H2. General Motors Corporation bills the H2 as having a cargo bed that "uses about seven pounds of molded in colour nanocomposite parts for its trim, centre bridge, sail panel and box rail protector."

A burgeoning industry has been created off the back of the nanotech process and, due to material properties fundamentally changing as products get smaller, there is a need for instrumentation to measure and analyse coatings on a nano scale.

The importance of nanometer coatings

Coatings with thicknesses of only a few micrometers or even only a few tens or hundreds of nanometers are gaining in importance due to their excellent properties. Hard material coatings of TiN, TiC or Diamond Like Carbon with thicknesses of 1 to 4 micrometers are already common for tools and engine components. Highly complex coating systems in the nanometer range have been developed over the past years to achieve scratch-resistant, soil-resistant, antistatic, reflecting or storage capable surfaces. The determination of the technological properties of such coatings is essential for their optimisation and the Picoindentor nano hardness testing instrument has evolved as the answer, offering enormous scope.

Measuring the properties of micro hardness and nano hardness coatings

The Picoindentor HM500 nano hardness tester can be used to determine the Martens Hardness HM characteristic elastic quantities and additional material parameters, even in the nanorange, using the instrument nanoindentation test accruing to DIN EN ISO 14577-1.

Excellent price/performance ratio

The Picoindentor nano hardness instrument distinguishes itself by its simple handling and its excellent price/performance ratio. The achieved resolution and accuracy for the load and distance measurement is in the same range as that of instruments with a much higher purchase price. Through its practical design with programmable XY stage and clear presentation of the measurement results, in comparison to other instruments, the Picoindentor nano hardness tester is not only suitable for laboratory applications but also the productions area.

The Microhardness and Nanohardness Measurement Principle

Hardness and other important material characteristics of thin coatings, either galvanically deposited or generated through a hardening process, are calculated using load/indentation depth method, otherwise called “the Martens Hardness HM” to differentiate it from the conventional hardness value determined according to Vickers.

With this method, the indenter – typically a Vickers or Berkovich pyramid – is continuously pressed into the material tested with an increasing test load, and then unloaded. The indentation depth of the pyramid is measured continuously during this penetration process. The hardness value HM is calculated from the selected maximum test load and the resultant indentation depth.

Microhardness and Nanohardness Applications

Nano hardness applications are far ranging and span many industries. The Picoindentor hardness tester is suited to hard material coatings, ultra thin DLC coatings, protective coatings on glass, soil resistant or sol-gel coatings, coatings of PC hard disks and CD’s, very thin paint coatings, ion implanted surfaces, nanocoatings for sensors, medical technology applications – implants for example, matrix effects in alloys, biological materials, ceramic materials.

Click here for a pdf brochure of the Picoindentor nano hardness testing instrument

Click here for a pdf brochure of the HM2000 micro hardness tester and Picoindentor hardness testers

Application example: Nano Measurements on Spectacle Lenses

These measurements on spectacle lenses indicate the effects of using a high load on a thin hard coating with a softer substrate. The steady decline of the curve as the load is applied shows the elastic behavior of the s ubstrate, the coating is pressed into the substrate as if it were a pillow. A much lower load of around 0.5mN should be selected, giving an indentation depth in the region of 150nM.