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New “Hydro-method” for measurement of surface appearance

April 16, 2019

Hydro Rolled Products has developed the “Hydro-method” together with Polytec throughout the last couple of years. This is a new method of measuring the surface appearance of aluminium, especially targeting the automotive industry.

The requirements of the automotive manufacturers towards the body of their cars have constantly grown in recent years. Good formability, sufficient strength, good corrosion resistance, recyclability and last but not least the appearance of the surface are key factors for car manufacturers like BMW, Audi and Daimler.

“We saw the need to develop a new surface measurement method. Together with our R&D colleagues in Bonn we invented the “Hydro-method”, a new method that enables us to describe the surface appearance faster, cheaper, operator independent and at higher accuracy compared to the standard method,” says Hendrik-Johan Brinkman, Head of Technical Customer Service and Product Development Automotive at Rolled Products.

“In this project we could unite Hydro’s expertise with Polytec’s know-how in white-light interferometers to improve surface appearance and roping,” says Tan Oezguer, Product Manager at Polytec.

What is the “Hydro-method”?

“Roping” – linear patterns on the surface of formed aluminium - is a commonly known surface phenomenon. A reduction of roping patterns is possible through adaption of process conditions through the entire process chain.  Today, the used method to quantify the roping value is the roping test according to VDA 239-400.  The “Hydro-method” is a faster, more economical and more precise way of measuring.

The “Hydro-method” uses the white light interferometer TMS-500 TopMap Pro Surf from Polytec to automatically measure the surface topography of sheet samples and determine the roping value. Polytec addresses surface metrology applications with innovative, high-precision, non-contact optical technology.

“With the “Hydro method” we are able to characterize the surface topography of our material with a high accuracy. Our customers appreciate our new method. Through our optimizations we could improve the surface appearance at our customers products,” says Hendrik-Johan Brinkman.

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