Strength of multilayer metal joints «shaft-sleeve-hub» of rotorcrafts obtained by plastic deformation

Metal multilayer joints are used in the production and repair of transmission parts and control systems of rotorcrafts with intensively wearing surfaces in the form of smooth closed cylindrical and conical holes. The article describes two types of connections: rolled sleeve - hub and shaft - rolled sleeve - hub. The adhesion strength of the joints depends on the frictional forces that prevent the sleeve from displacing relative to the hub. The traction strength is determined by measuring the pressing force and the torque. It depends on the relative tension. An increase in the force of pressing the joint occurs with an increase in the relative tension of mandrel, in proportion to the hardening of the material. The smaller hub wall thickness leads to the more active effect of its springback to the foundation of contact pressure and an increasing of the traction force. Experiments have shown that the forces and moments of traction depend on the angle of the intake cone and the width of the cylindrical tape of the mandrel.

Anisotropic MOF-on-MOF Growth of Isostructural Multilayer Metal–Organic Framework Heterostructures

Isostructural MOFs with similar crystallographic parameter are easily available for MOF-on-MOF growth and possible to form core–shell structure by isotropic growth. However, due to well-matched cell lattice, selective growth in isostructural MOF heterostructures remains a great challenge for engineering atypical MOF heterostructures. Herein, an anisotropic MOF-on-MOF growth strategy was developed to structure a range of multilayer sandwich-like ZIF-L heterostructures via stacking isostructural ZIF-L-Zn and ZIF-L-Co alternately with three-, five-, seven-, and more layer structures. Moreover, these heterostructures with highly designable feature were fantastic precursors for fabricating derivatives with tunable magnetic and catalytic properties. Such strategy explores a novel way of achieving anisotropic MOF-on-MOF growth between isostructural MOFs and opens up new horizons for regulating the properties by MOF modular assembly in versatile functional nanocomposites.

Optical bistability in reflection from multilayer metal-dielectric structure with Kerr nonlinearity

Both static and dynamic characteristics of light reflected from a specially designed multilayer metal-dielectric structure with Kerr nonlinearity have been studied in this work. Various regimes of nonlinear reflection from the structure have been demonstrated, including bistable switching between low and high reflection states, which occurs at low intensity of the incident light due to a significant enhancement in the optical field in the nonlinear layer under conditions of total internal reflection. This nonlinear structure has been proposed to use as an optically controlled intracavity laser modulator.

Enhanced broadband absorption with twisted multilayer metal-dielectric stacking metamaterial

This paper proposes and experimentally demonstrates the enhanced broadband absorption with twisted multilayer metal-dielectric stacking. Compared with the traditional metal-dielectric pyramid, the resonance frequencies of the third-order magnetic resonances in...

FIBROUS COMPOSITE MATERIALS WITH A METAL MATRIX (review)

The article provides an overview of the literature in the field of composite materials (CM) based on metal matrices reinforced with carbon fibers. The main structural, physical and mechanical properties and morphology of such CMS are briefly described. The structure and properties of new CMS from multilayer metal-intermetallic multilayer laminates reinforced with carbon and ceramic fibers are also presented. Application of the method of ultrasonic consolidation for the manufacture of multilayer fibrous CMs based on metal-intermetallic laminates provides high adhesion of fibers with an intermetallic layer.