High-temperature crack behavior of Si-rich TiAlSiN coatings
Year: 2026
Type: article
Abstract: TiAlSiN coatings are widely used to improve the performance and durability of cemented carbide cutting tools exposed to high mechanical and thermal stress. Elevated temperatures can promote crack formation, while silicon enhances microstructural stability and oxidation resistance. In this study, TiAlSiN coatings with silicon contents of x Si ∈ {8; 14; 20; 25} at.% in the metal portion were deposited. The effect of silicon content on coating morphology, indentation hardness H IT , indentation modulus E IT , and crack resistance was analyzed. High-temperature nanoindentation was performed from 23 °C ≤ T NI ≤ 400 °C. Crack resistance was evaluated by quasi-static high-load nanoindentation tests with loads 500 mN ≤ F NI ≤ 1750 mN at RT ≤ T NI ≤ 600 °C with subsequent scanning electron microscopy analysis. With rising silicon content, morphology became more irregular, indicating a fine-crystalline to amorphous structure. At room temperature, hardness increased up to x Si = 14 at.% with H IT = (26.37 ± 1.92) GPa before decreasing for higher Si contents. After cooling back to T = RT all coatings showed similar hardness values as before heating. At T = 400 °C, the maximum decrease in hardness was Δ H IT = −20% for x Si = 14 at.% while the x Si = 20 at.% coating exhibited the highest hardness with H IT = (21.8 ± 1.03) GPa. With increasing temperature, the critical load for initial crack formation decreased for lower Si contents but remained constant for higher Si levels. Under most severe conditions with F NI = 1750 mN and T = 600 °C, the coating with x Si = 25 at.% exhibited fewest cracks.
Source: Surface and Coatings Technology
Institution: RWTH Aachen University
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,880
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W7171408834