Higher life expectancy of coated tools by means of image processingHard material coated tools have substantially higher life expectancy of a tool compared to uncoated ones. Mainly because of this reason and because of the reduction of friction coefficient coated tools are being applied more and more widely. Within the tool industry it is especially evident at modern production methods such as High- Speed- Cutting, Hard- Material- Fine- Machining and Dry Machining. The quality of the coated precision tools and components is determined mainly by the adhesion of thin hard material layer with a basic tool. The estimation of adhesive strength is therefore of extreme importance for the quality according to ISO EN 9000-9004 for the producer as well as for the user of coated tools and components. By means of advanced image processing system and high performance computing it is now possible to monitor the quality of coatings under an industrial environment in a short evaluation time. Test method For the quality estimation
of thin hard material layers on precision tools (Fig. 1) and components
one needs a practice relevant test method. The method which makes it possible
is the so-called Rockwell indentation test (Fig. 2). The test is being
carried out up to now manually and is mostly spread in industry beside
the scratch test. The subjectivity of a testing person effects test results
negatively. A new and promising way is that on the base of Rockwell indentation
by means of image processing and under application of Neural Networks.
The adhesive strength can be stated objectively as the most
important criteria for the estimation of thin hard material layers.
 After indentation of a Rockwell
diamond on a coated tool or component with a definite strength the appeared
surrounding area is captured with a colour CCD-camera. The surrounding
area (Fig. 3) is characterised through a crack network and outbreaks of
coating.
 Now the image data are pre-processed. Following the non-linear classification problem is being carried out by means of Neural Networks and high performance computing technique. The result is the correct adhesive strength class according to a specific guideline in the tool industry. This test method allows an objective determination of the adhesive strength of thin hard material layers in an industrial environment in a short evaluation time of few seconds. Benefits for users The raising demands of coated tools and components as well as constantly raising demands on quality require more and more coating companies and sers of coated tools and components to apply relevant and economical test methods. With the Rockwell indentation test method the companies gain following benefits. The most important direct benefits of the solution are:
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