The creation of stacking fault in Al4SiC4 crystal structure due to a phonon mode (E1, 139.7 cm−1, Raman active) at Γ-point with negative mode-Grüneisen constant (−0.28). (a) 3-D side-view; (b) 2-D side view.
The mechanical and thermodynamic properties of intermetallic compounds in the Ni–Ti system are studied by first-principles calculations. All phases show anisotropic elasticity in different crystallographic directions, in which Ni3Ti and NiTi2 are approaching the isotropy structure. The elastic moduli and Vicker’s hardness of Ni–Ti system intermetallic compounds decrease in the following order: Ni3Ti [Formula: see text] B2_NiTi [Formula: see text] B19[Formula: see text]_NiTi [Formula: see text] NiTi2, and Ni3Ti shows the best mechanical properties. The intrinsic ductile nature of Ni–Ti compounds is confirmed by the obtained [Formula: see text]/[Formula: see text] ratio. The temperature dependence of linear thermal expansion coefficients (LTECs) of the compounds is estimated by the quasi-harmonic approximation (QHA) method. Ni3Ti shows the largest values among all Ni–Ti intermetallic compounds. At room temperature, the LTEC for Ni3Ti is 8.92 × 10[Formula: see text] K[Formula: see text], which falls in between the LTEC of zirconia toughened alumina (ZTA) (7.0–9.5 × 106 K[Formula: see text]) and iron matrix (9.2–16.9 × 106 K[Formula: see text]); i.e., the thermal matching of the ZTA/iron composite will be improved by introducing Ni3Ti intermetallic compound into their interface. Other thermodynamic properties such as sound velocity and Debye temperature are also obtained.
Ceramic particle reinforced iron matrix composites are one of the most promising wear resistant materials for tough conditions. Up to now, varieties of methods have been developed to fabricate this material, e.g. the infiltration casting process, which is especially beneficial to prepare the surface composite. Based on this method, a honeycomb structure of surface composite has been designed aiming to increase its toughness and interface strength. Moreover, zirconia toughened alumina (ZTA) is a perfect choice of reinforcement for wear resistant composite under high impact. The wettability between ZTA particle and iron matrix is a key factor to determine the performance of composite; the wettability can be improved by introducing active elements into their interface.
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.