Identification of oxidation process of TiALN coatings versus heat resistant aerospace alloys based on diffusion couples and tool wear tests

The Oxidation Behaviour and Notch Wear Formation of TiAlN Coated Tools Using Different Oxidation Techniques

“…The corresponding values of the thicknesses of oxidized layers for different oxidation times equal to 2.5 min, 10 min and 30 min calculated using Equation 1 shortest time of 2.5 min the mass increment (bars 1 and 3 in sections for TiAlN and TiAlN + Ti6Al4V) increased by 70% and 130% in comparison to about 12% and 22% when the annealing was continued up to 30 min for diffusion couples including IN718 and Ti6-4 coupons, respectively. This is because the relation of mass increment versus oxidation time is not linear but fits a logarithmic function [13]. The corresponding values of the thicknesses of oxidized layers for different oxidation times equal to 2.5 min, 10 min and 30 min calculated using Equation 1 It can be concluded based on the estimations presented in Figure 3 that the thickness of the oxidized layer increases by about three times when the annealing time increases from 2.5 to 10 min.…”

“…On the other hand, in the case of Ti alloys oxidized in high temperature, the mixture of Al 2 O 3 and TiO 2 are produced, however the Al 2 O 3 oxide scale is thermodynamically more stable at 900 • C [15].The annealing time influences the oxidation effects in such a way that for the shortest time of 2.5 min the mass increment (bars 1 and 3 in sections for TiAlN and TiAlN + Ti6Al4V) increased by 70% and 130% in comparison to about 12% and 22% when the annealing was continued up to 30 min for diffusion couples including IN718 and Ti6-4 coupons, respectively. This is because the relation of mass increment versus oxidation time is not linear but fits a logarithmic function [13]. The corresponding values of the thicknesses of oxidized layers for different oxidation times equal to 2.5 min, 10 min and 30 min calculated using Equation 1 shortest time of 2.5 min the mass increment (bars 1 and 3 in sections for TiAlN and TiAlN + Ti6Al4V) increased by 70% and 130% in comparison to about 12% and 22% when the annealing was continued up to 30 min for diffusion couples including IN718 and Ti6-4 coupons, respectively.…”

Investigation of notch wear mechanisms in the machining of nickel-based Inconel 718 alloy

“…The diffusion couples consisting of TiAlN coated inserts and special coupons (see Fig. 1) made of Inconel 718 alloy in the form of 2 mm thick plates were annealed at the constant temperature of 900°C during variable time of 2.5, 10 and 30 min [13].…”

“…The oxidation effect was assessed by measurements of the mass before and after annealing using a precision weighting with the resolution of ±0.1 mg [13]. As a result, the mass of the deposited top Al203 layer by area unit (mol) was determined and its thickness (tol) was assessed from Eq.…”

“…Previously, the experimental study on the application of diffusion couple method to detect the oxidation process between TiAlN coating and Inconel 718 was presented in Ref. [13]. The obtained data were compared with tool wear tests under dry machining conditions and different machining times.…”