Control of heterointerfaces in advanced composite materials is of scientific and industrial importance, because their interfacial structures and properties often determine overall performance and reliability of the materials. Here distinct improvement of mechanical properties of alumina-matrix tungsten-carbide composites, which is expected for cutting-tool application for aerospace industries, is achieved via interfacial atomic segregation. It is found that only a small amount of Zr addition is unexpectedly effective to significantly increase their mechanical properties, and especially their bending strength reaches values far beyond those of conventional superhard composite materials. Atomic-resolution STEM observations show that doped Zr atoms are preferentially located only at interfaces between Al2O3 and WC grains, forming atomic segregation layers. DFT calculations indicate favorable thermodynamic stability of the interfacial Zr segregation due to structural transition at the interface. Moreover, theoretical works of separation demonstrate remarkable increase in interfacial strength through the interfacial structural transition, which strongly supports reinforcement of the interfaces by single-layer Zr segregation.
Electronic and atomic structures of interfaces between TiN coatings and Al2O3–WC composites were investigated by Density functional theory (DFT) calculations. As typical examples, interfacial orientation relationships of TiN(001)/Al2O3(0001), TiN(001)/WC(0001), TiN(111)/Al2O3(0001), and TiN(111)/WC(0001) were chosen. It was found that the TiN(111)/Al2O3(0001) and TiN(111)/WC(0001) interfaces have interfacial structural units of six‐fold coordinated triangular prisms centered on Ti atoms. In contrast, those of the interfaces with TiN(001) tend to have more distorted structure units due to their larger lattice misfits. Theoretical works of separation showed that interfacial strength is much more increased at the TiN(111) interfaces, as compared to those at the TiN(001) interfaces. Accordingly, experimental controls of TiN‐coating orientations on Al2O3–WC composites were attempted by using the cathodic arc ion plating method. It was found that orientations of (111) in the TiN coatings can be more enhanced and then interfacial mechanical strengths and hardnesses of the TiN coatings can increase more with rising bias voltages.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.