Strategies for damage tolerance enhancement in metal/ceramic thin films: Lessons learned from Ti/TiN

Assessing the Fracture and Fatigue Resistance of Nanostructured Thin Films

“…Consequently, the fracture toughness values for the Cr thin film should be treated carefully, especially when compared to results deduced from different procedures. Overall, the results for the Cr thin film are considerably lower in contrast to the bulk material fracture toughness [69] -a known effect for sputter deposited metallic thin films [70] (see Table 2 ). Upon specifically regarding the elastic deformability of the thin films, all Cr-based compounds show a comparable maximum bending strain in the range of ε = 1-1.2 %, whereas the metallic coating exhibits an extended displacement up to w > 1.5 μm and ε > 1.5 % prior to failure.…”

Characterization and Simulation of Nanoscale Catastrophic Failure of Metal/Ceramic Interfaces

“…Note that interplanar traction t int > 0 at the catastrophe point; then, one can derive the slope of the interface cohesive curve at the catastrophe point (7) It is interesting that the interfacial catastrophic failure does not occur at the peak interface traction but somewhere after it. When the interface system contains a sufficiently large number of atomic layers (N C → ∞, N M → ∞), , i.e., the catastrophe point coincides with the peak interface traction point.…”

“…Layered metal–ceramic composites, which integrate the advantages of metal (e.g., ductility, electrical conductivity) and ceramics (e.g., high strength, chemical resistance), are key to many technological applications such as electronic devices, − thermal barrier coatings (TBC), − and semiconductors. , The metal/ceramic interface is a crucial component of layered metal–ceramic composites, and the adhesion of this interface plays a pivotal role in dominating the mechanical, thermal, and electrical properties of the composites . Because of differences in the lattice structure and properties (e.g., Young’s modulus, coefficient of thermal expansion (CTE)) between metals and ceramics, defects such as misfit dislocations appear at the interface, weakening the interface bonding and decreasing the effective interface area .…”

Atomic-Scale Insights into the Self-Assembly of Alternating AlN/TiN Lamellar Nanostructures via Spinodal Decomposition in AlTiN Coating

“…7−9 This nanolamella profoundly affects the composition and microstructure of the coatings and therefore is crucial to the outstanding functional properties of the coatings. 10,11 However, the formation mechanism of such nano-lamellar structures is still open for researchers, and the role of dislocation in the nanolamellar formation process remains unknown, which has been a fundamental problem in AlTiN coating studies for a long time.…”

“…As an excellent hard coating widely used in industrial production, AlTiN coating can greatly improve the physical properties and service life of tools. , The most fascinating aspect of the face-centered cubic (fcc)-AlTiN coating is its nano-lamellar composite structure which is characterized by a lamellar structure constituted by Ti­(Al)N (TiN for short) and Al­(Ti)N (AlN for short) nano-lamellae alternately. − The thickness of the lamella, the ratio of the thickness between the AlN and TiN lamellae, the misfit dislocations at AlN-TiN interfaces, and the phase transitions under loading all contribute to the extraordinary hardness, fracture toughness, and oxidation resistance of the AlTiN coatings. − This nano-lamella profoundly affects the composition and microstructure of the coatings and therefore is crucial to the outstanding functional properties of the coatings. , However, the formation mechanism of such nano-lamellar structures is still open for researchers, and the role of dislocation in the nano-lamellar formation process remains unknown, which has been a fundamental problem in AlTiN coating studies for a long time.…”