TY - JOUR

T1 - Influence of multilayer architecture on microstructure and fracture properties of arc evaporated TiAlTaN coatings

AU - Waldl, Helene

AU - Tkadletz, Michael

AU - Czettl, Christoph

AU - Pohler, Markus

AU - Schalk, Nina

N1 - Publisher Copyright: © 2022 The Author(s)

PY - 2022/3/15

Y1 - 2022/3/15

N2 - The incorporation of a fourth element in Ti 1-xAl xN, like Ta, and a multilayer architecture are possible concepts to further enhance the coating performance in cutting applications. In the present study, both concepts are combined, focusing on the investigation of the microstructure and the fracture properties of two Ti 1-x-yAl xTa yN single layer coatings (Ti 0.55Al 0.44Ta 0.01N and Ti 0.33Al 0.54Ta 0.13N) and two corresponding multilayer coatings with the same bilayer thickness but an inverse layer sequence with different layer thicknesses. Energy dispersive X-Ray spectroscopy was utilized to determine the average composition of the coatings, confirming that the Al and Ta contents increase from single layer Ti 0.55Al 0.44Ta 0.01N via the two multilayers to single layer Ti 0.33Al 0.5 4Ta 0.1 3N. The residual stress and microstructure were studied using X-ray diffraction and scanning electron microscopy revealing higher compressive stress and grain refinement with higher Al and Ta content, which provoked an increasing hardness as evidenced by nanoindentation experiments. In contrast, the contribution of the multilayer architecture to the hardness increase is only minor. Additionally, micromechanical bending tests revealed a trend of higher fracture stress with increasing Al and Ta content. The fracture toughness was constant for all coatings as different toughening mechanisms occur.

AB - The incorporation of a fourth element in Ti 1-xAl xN, like Ta, and a multilayer architecture are possible concepts to further enhance the coating performance in cutting applications. In the present study, both concepts are combined, focusing on the investigation of the microstructure and the fracture properties of two Ti 1-x-yAl xTa yN single layer coatings (Ti 0.55Al 0.44Ta 0.01N and Ti 0.33Al 0.54Ta 0.13N) and two corresponding multilayer coatings with the same bilayer thickness but an inverse layer sequence with different layer thicknesses. Energy dispersive X-Ray spectroscopy was utilized to determine the average composition of the coatings, confirming that the Al and Ta contents increase from single layer Ti 0.55Al 0.44Ta 0.01N via the two multilayers to single layer Ti 0.33Al 0.5 4Ta 0.1 3N. The residual stress and microstructure were studied using X-ray diffraction and scanning electron microscopy revealing higher compressive stress and grain refinement with higher Al and Ta content, which provoked an increasing hardness as evidenced by nanoindentation experiments. In contrast, the contribution of the multilayer architecture to the hardness increase is only minor. Additionally, micromechanical bending tests revealed a trend of higher fracture stress with increasing Al and Ta content. The fracture toughness was constant for all coatings as different toughening mechanisms occur.

UR - http://www.scopus.com/inward/record.url?scp=85122644211&partnerID=8YFLogxK

U2 - 10.1016/j.surfcoat.2022.128098

DO - 10.1016/j.surfcoat.2022.128098

M3 - Article

VL - 433.2022

JO - Surface & coatings technology

JF - Surface & coatings technology

SN - 0257-8972

IS - 15 March

M1 - 128098

ER -