TY - JOUR

T1 - Phase stability and enhanced mechanical properties of nanocrystalline PVD CrCu coatings

AU - Burtscher, Michael

AU - Kainz, Christina

AU - Dorner, Paola

AU - Fellner, Simon

AU - Terziyska, Velislava

AU - Alfreider, Markus

AU - Kiener, Daniel

N1 - Publisher Copyright: © 2025 The Authors

PY - 2025/1/8

Y1 - 2025/1/8

N2 - The current work investigates the possibility of strengthening grain boundaries by nanoprecipitates using a CrCu coating model system. To this end, two compositions with 30 and 40 at.% of Cu and a balanced amount of Cr were synthesized via physical vapor deposition. The coatings exhibited a thickness of 1.8 μm and a Cr-based solid solution was determined for both systems in the as-deposited state. The precipitation of Cu upon annealing was determined via high-temperature X-ray diffraction analysis. Furthermore, nanoindentation measurements on heat-treated specimens showed a peak hardness and Young's modulus after 400 °C annealing for both coatings. Heating experiments in the transmission electron microscope verified the related formation of nano-scaled Cu precipitates. The conditional fracture toughness and resulting J-Integral were determined for the as-deposited and selected heat-treated states utilizing micromechanical notched cantilever experiments. The annihilation of microstructural defects and the precipitation of nm-sized Cu precipitates within and along the columnar Cr are regarded as the primary strengthening mechanisms. This statement is verified by the appearance of the individual fracture surfaces and proves that tailored precipitation of nm-sized Cu particles is a viable strategy to effectively boost the fracture mechanical properties of physical vapor-deposited CrCu alloys.

AB - The current work investigates the possibility of strengthening grain boundaries by nanoprecipitates using a CrCu coating model system. To this end, two compositions with 30 and 40 at.% of Cu and a balanced amount of Cr were synthesized via physical vapor deposition. The coatings exhibited a thickness of 1.8 μm and a Cr-based solid solution was determined for both systems in the as-deposited state. The precipitation of Cu upon annealing was determined via high-temperature X-ray diffraction analysis. Furthermore, nanoindentation measurements on heat-treated specimens showed a peak hardness and Young's modulus after 400 °C annealing for both coatings. Heating experiments in the transmission electron microscope verified the related formation of nano-scaled Cu precipitates. The conditional fracture toughness and resulting J-Integral were determined for the as-deposited and selected heat-treated states utilizing micromechanical notched cantilever experiments. The annihilation of microstructural defects and the precipitation of nm-sized Cu precipitates within and along the columnar Cr are regarded as the primary strengthening mechanisms. This statement is verified by the appearance of the individual fracture surfaces and proves that tailored precipitation of nm-sized Cu particles is a viable strategy to effectively boost the fracture mechanical properties of physical vapor-deposited CrCu alloys.

KW - CrCu

KW - in situ TEM

KW - Micro-mechanic

KW - Precipitation

KW - PVD

UR - http://www.scopus.com/inward/record.url?scp=85214496109&partnerID=8YFLogxK

U2 - 10.1016/j.jmrt.2025.01.020

DO - 10.1016/j.jmrt.2025.01.020

M3 - Article

AN - SCOPUS:85214496109

VL - 35.2025

SP - 369

EP - 378

JO - Journal of Materials Research and Technology

JF - Journal of Materials Research and Technology

SN - 2238-7854

IS - March-April

M1 - 35

ER -