Solid state formation of Ti4AlN3 in cathodic arc deposited (Ti1−xAlx)Ny alloys

Abstract

Reactive cathodic arc deposition was used to grow substoichiometric solid solution cubic c-(Ti 1-x Al x)N y thin films. The films were removed from the substrate and then heated in an argon environment to 1400 °C. Via solid state reactions, formation of MAX phase Ti 4 AlN 3 was obtained. Additional phases such as Ti 2 AlN, c-TiN, w-AlN, Al 5 Ti 2 and Al 3 Ti were also present during the solid state reaction. Ti 4 AlN 3 formation was observed in samples with an Al metal fraction x < 0.63 and a nitrogen content 0.4 < y < 0.6. Regardless of the initial composition, formation of Ti 4 AlN 3 started in Ti 2 AlN crystal plates in the temperature range between 1200-1400 °C. Accompanying the onset of Ti 4 AlN 3 was the presence of an intermediate structure identified as Ti 6 Al 2 N 4 , consisting of alternating layers of intergrown Ti 2 AlN and Ti 4 AlN 3 phases with a half-unit-cell stacking. We suggest that the formation of Ti 4 AlN 3 occurred via intercalation of aluminum and nitrogen along the basal plane accompanied by a simultaneous detwinning process. In addition we propose that this formation mechanism can be used to obtain MAX phases of high n order.

Synthesis and Characterization of a Nearly Single Bulk Ti2AlN MAX Phase Obtained from Ti/AlN Powder Mixture through Spark Plasma Sintering

“…The reduced amounts of the ancillary phases are associated with an intermediate phase for the case of the TiN that is related to the formation mechanism of the Ti 2 AlN MAX phase [ 23 ]. On the other hand, the Ti 4 AlN 3 corresponds to a high-order MAX phase and its production and the mechanism of the formation have been scarcely reported [ 35 , 38 , 39 ]. It is observed that by increasing the sintering temperature, the XRD peaks of the Ti 4 AlN 3 disappeared and, simultaneously, the relative intensity of the TiN peaks increased.…”

TiCrN-TiAlN-TiAlSiN-TiAlSiCN multi-layers utilized to increase tillage tools useful lifetime

“…7 research on TiAlN-TiAlSiN double layers also revealed a high level of hardness of the coated tools for cutting applications. Along with research conducted on TiAlSiN, TiAlSi 46 , TiAlN 30,47–50 and TiN-TiAlN 44 multi-layers have also been deposited by arc-PVD method, which have shown promising mechanical properties. For many years, researchers investigated simple single layer coatings to increase wear and oxidation resistance of cutting tools.…”

Processing of MAX phases: From synthesis to applications

“…The high energetic arc generates a high degree of ionization of the deposition flux, almost 100%, which might reduce the synthesis temperature. 138,139 This process leads to a fine control of the final composition and in some specific cases even lower synthesis temperature, such as for Ti 2 AlN. 132 Thick films can be obtained due to the high degree of ionization, but the powerful energies produce a negative effect, which is the presence of macroparticles embedded into the film.…”

“…The process is based on the vaporization from typically three cathode targets (M, A, and X elements) caused by a pulsed high current and low voltage arc. The high energetic arc generates a high degree of ionization of the deposition flux, almost 100%, which might reduce the synthesis temperature 138,139 . This process leads to a fine control of the final composition and in some specific cases even lower synthesis temperature, such as for Ti 2 AlN 132 .…”