W. Kalss - Academia.edu (original) (raw)

Papers by W. Kalss

Fresenius' Journal of Analytical Chemistry, 1997

Surface and Coatings Technology, 2008

Standard θ-2θ and pole figure X-ray diffraction techniques were used to study structural properti... more Standard θ-2θ and pole figure X-ray diffraction techniques were used to study structural properties and preferred orientation of nanostructured TiAlN thin films prepared using cathodic arc deposition. Systematic collection of reflections from lattice planes {111}, {200}, {220}, and {311} showed that the in-plane orientation of crystallites exhibits cylindrical symmetry with random distribution of crystallites, while the out-of-plane growth presents strong texture which is inclined with respect to the surface normal. This brings the crystallographic orientation of fibre texture towards high indices lattice planes and contrary to traditionally grown films that develop a preferred orientation following to low indices close-packed planes and . The origin of inclined growth is discussed taking into account the role of crystallographic defects in particular twin faults that develop in the lattice of growing crystal and change the stacking sequences of atom layers.

International Journal of Refractory Metals and Hard Materials, 2006

Modern, state-of-the-art, PVD coatings are required to fulfill a variety of different application... more Modern, state-of-the-art, PVD coatings are required to fulfill a variety of different applications. Each metal cutting operation requires an optimal combination of various film parameters to achieve a high end cutting performance. Especially, Al-based coatings such as AlTiN-and AlCrN-coatings show very good results in high performance metal cutting applications.

International Journal of Refractory Metals and Hard Materials, 2010

Diamond deposition on various hardmetal tools is widely used. For applications where the mechanic... more Diamond deposition on various hardmetal tools is widely used. For applications where the mechanical forces are low diamond coatings have long lifetimes, but especially for heavy duty applications the reproducibility of the diamond coating adhesion is not adequate.

Diamond and Related Materials, 1997

ABSTRACT

Diamond and Related Materials, 1998

ABSTRACT

Surface and Coatings Technology, 2007

Ex-situ X-ray diffraction was used to characterize the stress state and texture of TiAlN monolaye... more Ex-situ X-ray diffraction was used to characterize the stress state and texture of TiAlN monolayer and TiN/TiAlN multilayer hard coatings deposited on WC-Co and tool steel substrates using the cathode arc evaporation method. For all coatings the compressive residual stress was found to be higher in the film deposited on tool steel than that deposited on WC-Co; this is due to the difference in the linear thermal expansion coefficient of the two substrates. X-ray diffraction polar scan measurements showed that the preferred orientation of the crystallites exhibits cylindrical symmetry but it is inclined with respect to the sample surface. Moreover, the inclination angle of the (002) diffracting planes increases with the increase of the residual stress in the coating. Different mechanisms that could explain the interdependence between fiber texture and residual stress are discussed.

International Journal of Refractory Metals and Hard Materials, 1996

ABSTRACT Diamond coatings were produced by the hot-filament method, adding B(C2H5)3 to the gas ph... more ABSTRACT Diamond coatings were produced by the hot-filament method, adding B(C2H5)3 to the gas phase. We compared the results on WC-Co hardmetal and Si substrates. SIMS-measurements revealed high B contents in diamond layers on WC-Co substrates accompanied by high amounts of Co. TEM showed CoB and CO2B inclusions in the diamond layer. Furthermore, B-diffusion in the WC-Co bulk was shown. On Si substrates, crystal quality and growth rate decreased at high B concentrations. Higher B contents were found in the diamond layer than were used in the gas phase.

International Journal of Refractory Metals and Hard Materials, 1998

is a preliminary trial to grow cubic BN or cubic ternary B-C-N phases without application of high... more is a preliminary trial to grow cubic BN or cubic ternary B-C-N phases without application of high pressure.

Diamond and Related Materials, 1998

ABSTRACT

Diamond and Related Materials, 1999

Whereas the low-pressure synthesis of diamond from the gas phase has become a well-established te... more Whereas the low-pressure synthesis of diamond from the gas phase has become a well-established technology, equivalent low-pressure c-BN synthesis is not yet possible. So far, macroscopic crystalline c-BN powders can only be synthesized by high-pressure/high-temperature methods. For a successful low-pressure synthesis of c-BN, both nucleation and, subsequently, a continuous growth on appropriate solid substrate materials are required. It is shown that heteroepitaxial c-BN nucleation and growth do occur on various solid materials from Li3BN2 melts at high pressure/high temperature. Random nucleation and growth of c-BN aggregates could be observed on various substrates, such as CVD diamond and B4C (single and polycrystalline) as well as on surface-treated refractory metal substrates. On B4C and on diamond substrates, even larger individual c-BN crystals could be grown, and on some substrates, even continuous layers occurred. Due to the polycrystalline nature of the substrates, any epitaxial c-BN nucleation was difficult to prove. From the present results, we can conclude that c-BN nucleation and growth do occur on the appropriate substrate materials, such as diamond and B4C.

Surface and Coatings Technology, 2009

In this study, cemented carbide ball nose end mills with nano-crystalline Al 0.67 Ti 0.33 N hard ... more In this study, cemented carbide ball nose end mills with nano-crystalline Al 0.67 Ti 0.33 N hard PVD coatings deposited by cathodic arc evaporation were annealed at 700°C during 2 h in a controlled atmosphere environment (argon + oxygen mixture) and in vacuum. The changes of structure and properties of the treated coating surfaces have been analyzed using both cross-sectional scanning electron microscopy (SEM) and x-ray absorption spectroscopy (XAS) of the N-K and O-K edges. Cutting tools have been run through ball nose end milling of hardened H13 steel (HRC 50) where temperature or stress dominating phenomena control tool life. The data obtained indicate that an AlTiN coated cutting tool can be modified upon annealing at low temperature conditions and should be considered as a composite surface engineered material. It is shown that increased tool life could be achieved if annealing of AlTiN is performed in an oxygen-containing atmosphere. A variety of different characteristics should be optimized to achieve better wear resistance of the cutting tools with annealed Al 0.67 Ti 0.33 N coating under high temperature and stress cutting conditions.

Fresenius' Journal of Analytical Chemistry, 1997

Surface and Coatings Technology, 2008

Standard θ-2θ and pole figure X-ray diffraction techniques were used to study structural properti... more Standard θ-2θ and pole figure X-ray diffraction techniques were used to study structural properties and preferred orientation of nanostructured TiAlN thin films prepared using cathodic arc deposition. Systematic collection of reflections from lattice planes {111}, {200}, {220}, and {311} showed that the in-plane orientation of crystallites exhibits cylindrical symmetry with random distribution of crystallites, while the out-of-plane growth presents strong texture which is inclined with respect to the surface normal. This brings the crystallographic orientation of fibre texture towards high indices lattice planes and contrary to traditionally grown films that develop a preferred orientation following to low indices close-packed planes and . The origin of inclined growth is discussed taking into account the role of crystallographic defects in particular twin faults that develop in the lattice of growing crystal and change the stacking sequences of atom layers.

International Journal of Refractory Metals and Hard Materials, 2006

Modern, state-of-the-art, PVD coatings are required to fulfill a variety of different application... more Modern, state-of-the-art, PVD coatings are required to fulfill a variety of different applications. Each metal cutting operation requires an optimal combination of various film parameters to achieve a high end cutting performance. Especially, Al-based coatings such as AlTiN-and AlCrN-coatings show very good results in high performance metal cutting applications.

International Journal of Refractory Metals and Hard Materials, 2010

Diamond deposition on various hardmetal tools is widely used. For applications where the mechanic... more Diamond deposition on various hardmetal tools is widely used. For applications where the mechanical forces are low diamond coatings have long lifetimes, but especially for heavy duty applications the reproducibility of the diamond coating adhesion is not adequate.

Diamond and Related Materials, 1997

ABSTRACT

Diamond and Related Materials, 1998

ABSTRACT

Surface and Coatings Technology, 2007

Ex-situ X-ray diffraction was used to characterize the stress state and texture of TiAlN monolaye... more Ex-situ X-ray diffraction was used to characterize the stress state and texture of TiAlN monolayer and TiN/TiAlN multilayer hard coatings deposited on WC-Co and tool steel substrates using the cathode arc evaporation method. For all coatings the compressive residual stress was found to be higher in the film deposited on tool steel than that deposited on WC-Co; this is due to the difference in the linear thermal expansion coefficient of the two substrates. X-ray diffraction polar scan measurements showed that the preferred orientation of the crystallites exhibits cylindrical symmetry but it is inclined with respect to the sample surface. Moreover, the inclination angle of the (002) diffracting planes increases with the increase of the residual stress in the coating. Different mechanisms that could explain the interdependence between fiber texture and residual stress are discussed.

International Journal of Refractory Metals and Hard Materials, 1996

ABSTRACT Diamond coatings were produced by the hot-filament method, adding B(C2H5)3 to the gas ph... more ABSTRACT Diamond coatings were produced by the hot-filament method, adding B(C2H5)3 to the gas phase. We compared the results on WC-Co hardmetal and Si substrates. SIMS-measurements revealed high B contents in diamond layers on WC-Co substrates accompanied by high amounts of Co. TEM showed CoB and CO2B inclusions in the diamond layer. Furthermore, B-diffusion in the WC-Co bulk was shown. On Si substrates, crystal quality and growth rate decreased at high B concentrations. Higher B contents were found in the diamond layer than were used in the gas phase.

International Journal of Refractory Metals and Hard Materials, 1998

is a preliminary trial to grow cubic BN or cubic ternary B-C-N phases without application of high... more is a preliminary trial to grow cubic BN or cubic ternary B-C-N phases without application of high pressure.

Diamond and Related Materials, 1998

ABSTRACT

Diamond and Related Materials, 1999

Whereas the low-pressure synthesis of diamond from the gas phase has become a well-established te... more Whereas the low-pressure synthesis of diamond from the gas phase has become a well-established technology, equivalent low-pressure c-BN synthesis is not yet possible. So far, macroscopic crystalline c-BN powders can only be synthesized by high-pressure/high-temperature methods. For a successful low-pressure synthesis of c-BN, both nucleation and, subsequently, a continuous growth on appropriate solid substrate materials are required. It is shown that heteroepitaxial c-BN nucleation and growth do occur on various solid materials from Li3BN2 melts at high pressure/high temperature. Random nucleation and growth of c-BN aggregates could be observed on various substrates, such as CVD diamond and B4C (single and polycrystalline) as well as on surface-treated refractory metal substrates. On B4C and on diamond substrates, even larger individual c-BN crystals could be grown, and on some substrates, even continuous layers occurred. Due to the polycrystalline nature of the substrates, any epitaxial c-BN nucleation was difficult to prove. From the present results, we can conclude that c-BN nucleation and growth do occur on the appropriate substrate materials, such as diamond and B4C.

Surface and Coatings Technology, 2009

In this study, cemented carbide ball nose end mills with nano-crystalline Al 0.67 Ti 0.33 N hard ... more In this study, cemented carbide ball nose end mills with nano-crystalline Al 0.67 Ti 0.33 N hard PVD coatings deposited by cathodic arc evaporation were annealed at 700°C during 2 h in a controlled atmosphere environment (argon + oxygen mixture) and in vacuum. The changes of structure and properties of the treated coating surfaces have been analyzed using both cross-sectional scanning electron microscopy (SEM) and x-ray absorption spectroscopy (XAS) of the N-K and O-K edges. Cutting tools have been run through ball nose end milling of hardened H13 steel (HRC 50) where temperature or stress dominating phenomena control tool life. The data obtained indicate that an AlTiN coated cutting tool can be modified upon annealing at low temperature conditions and should be considered as a composite surface engineered material. It is shown that increased tool life could be achieved if annealing of AlTiN is performed in an oxygen-containing atmosphere. A variety of different characteristics should be optimized to achieve better wear resistance of the cutting tools with annealed Al 0.67 Ti 0.33 N coating under high temperature and stress cutting conditions.