TY - THES

T1 - Ru alloyed TiAlN and CrAlN coatings prepared by cathodic arc evaporation

AU - Pohler, Markus

N1 - embargoed until null

PY - 2008

Y1 - 2008

N2 - Ti1-xAlxN and Cr1-xAlxN hard coatings produced by physical vapour deposition are successfully applied in cutting industry. The challenge of higher cutting speeds which results in increased cutting temperatures and the introduction of new difficult to machine engineering materials lead to the development of new quaternary coating systems based on TiAlN and CrAlN. In this way, an enhancement of the wear and oxidation resistance as well as the thermal stability of these coatings can be achieved. The aim of this work was to compare state-of-the-art TiAlN and CrAlN coatings and to evaluate the influence of the addition of small amounts of Ru on the properties of these coatings. Moreover, the effectiveness of multi-layer coating design has been evaluated. A series of Ru alloyed TiAlN and CrAlN coatings with an Al content of 67 and 70 at.%, respectively have been deposited in single layer and multi-layer architecture using a commercial arc evaporation coating plant. The structural and mechanical properties have been determined in the as deposited state and after vacuum annealing up to 1000°C. The results based on X-ray diffraction, microhardness measurements and ball on disc tribometer investigations at room temperature, 500°C and 700°C, show a notable influence of even small amounts of Ru on the properties and indicate high potential for precipitation hardening for both single layer and multi-layer coatings.

AB - Ti1-xAlxN and Cr1-xAlxN hard coatings produced by physical vapour deposition are successfully applied in cutting industry. The challenge of higher cutting speeds which results in increased cutting temperatures and the introduction of new difficult to machine engineering materials lead to the development of new quaternary coating systems based on TiAlN and CrAlN. In this way, an enhancement of the wear and oxidation resistance as well as the thermal stability of these coatings can be achieved. The aim of this work was to compare state-of-the-art TiAlN and CrAlN coatings and to evaluate the influence of the addition of small amounts of Ru on the properties of these coatings. Moreover, the effectiveness of multi-layer coating design has been evaluated. A series of Ru alloyed TiAlN and CrAlN coatings with an Al content of 67 and 70 at.%, respectively have been deposited in single layer and multi-layer architecture using a commercial arc evaporation coating plant. The structural and mechanical properties have been determined in the as deposited state and after vacuum annealing up to 1000°C. The results based on X-ray diffraction, microhardness measurements and ball on disc tribometer investigations at room temperature, 500°C and 700°C, show a notable influence of even small amounts of Ru on the properties and indicate high potential for precipitation hardening for both single layer and multi-layer coatings.

KW - Lichtbogenverdampfung Hartstoffschichten Ti1-xAlxN Cr1-xAlxN Ruthenium Mikrostruktur Tribologie Mikrohärte Aushärtung Vielschichtsystem

KW - cathodic arc evaporation hard coatings Ti1-xAlxN Cr1-xAlxN ruthenium microstructure tribology microhardness age hardening multi-layer

M3 - Diploma Thesis

ER -