Al-rich altin coating layers produced by pvd from metallic targets

A method for producing coated substrates involving deposition of at least one coating layer on a surface of a substrate, characterized in that:

• the at least one coating layer is synthesized in the interior of a vacuum coating chamber by using reactive PVD cathodic arc evaporation techniques, wherein:
• nitrogen gas is introduced in the vacuum coating chamber to be used as reactive gas,
• at least one arc evaporation source comprising a target material operated as cathode for evaporating the target material is used,
• the target material consisting of Al and Ti or comprising Al and Ti as main components, wherein if only considering the content of Al and Ti in atomic percentage in the target material, then the ratio of Al[at %]/Ti[at %] in the target material is of 70/30 or more, i.e Al [at %]/Ti [at %]≥70/30,
• the method involves a reactive deposition of aluminium titanium nitride as a result of a reaction between aluminium and titan from the target material with nitrogen from the nitrogen gas comprised in the coating chamber,
• the reactive deposition of aluminium titanium nitride on the substrate being carried out
• i. at a deposition temperature of less than 360° C.,
• ii. at a nitrogen partial pressure of less than 3 Pa by using a bias voltage Ub at the substrate in a range corresponding to −250 V≤Ub≤−30V.
• iii. the coating layer being formed:
• a. comprising Al, Ti and N as solely components or as main components and having chemical elements composition in atomic percentage regarding these elements according to formula (AlaTib)xNy, where a and b are respectively the concentration of aluminium and titanium in atomic ratio considering only Al and Ti for the calculation of the element composition in the layer, whereby a+b=1 and 0≠a≥0.7 and 0≠b≥0.2, and where x is the sum of the concentration of Al and the concentration of Ti, and y is the concentration of nitrogen in atomic ratio considering only Al, Ti and N for the calculation of the element composition in the coating layer, whereby x+y=1 and 0.45≤x≤0.55,
• b. exhibiting 90% or more of fcc cubic phase, and
• c. compressive stress of 2.5 GPa or more.