In this work, a new type of metal-organic coordination polymer (MOP) was developed with thermoplastic starch (TPS) by reactive extrusion with zinc acetate (ZA). The resulting material, denoted as T...

Facile Strategy to Construct Metal–Organic Coordination Thermoplastic Starch with High Hydrophobicity, Glass-Transition Temperature, and Improved Shape Recovery

The article presents a comparative characterization of the structural materials (composites and metals) used in modern aviation structures, focusing on the airframe structure of the most modern aircraft (Airbus A-380, Boeing B-787, and JSF F-35). Selected design and operational problems were analysed, with particular emphasis on composites and light metals (aluminium). For this purpose, the Shore’s method was used for the analysis of the obtained strength results and the programming environment (ANSYS, SolidWorks) required to simulate the GLARE 3 2/1-04 composite. The focus was on highlighting the differences in the construction and modelling of these materials resulting from their various structures (isotropy and anisotropy), e.g., by analyzing the mechanics of metal destruction and comparing it with the composite material. In terms of solving the problems of finite element analysis FEM, tests have been carried out on two samples made of an aluminium alloy and a fiberglass composite. The focus was on highlighting the differences in the construction and modelling of these materials resulting from their various structures (isotropy and anisotropy), e.g., by analyzing the mechanics of metal destruction and comparing it with the composite material. On the basis of the obtained results, the preferred variant was selected, in terms of displacements, stresses, and deformations. In the final part of the work, based on the conducted literature analysis and the conducted research (analysis, simulations, and tests), significant observations and final conclusions, reflected in practical applications, were formulated.

Practical Use of Composite Materials Used in Military Aircraft.

The effect of annealing of milled carbon fibers on the mechanical and tribological properties of solid‐lubricant thermoplastic polyimide‐based composites

In this research, an analysis of polymer composite with the matrix of L285-cured hardener H286 and six reinforcement layers of carbon fabric GG 280 T was provided. It involved a comparison of the dynamical behavior responses for three cases of composite structures in the context of the presence of the mass share modifier. The samples with the addition of a physical modifier with varying mass percentages were investigated by being subjected to dynamic tests with specific parameters, i.e., constant excitation amplitude and vibration frequency in the vicinity of the base resonance zone. The analysis allowed for indicating the relationship between the composition of the prepared composites and their dynamic response via stiffness characteristics. In addition, the investigation resulted in determining the range of harmful dynamical operating conditions, which may contribute to damage to the composite structures.

https://www.mdpi.com/1996-1944/13/23/5479/pdf

Influence of the Selected Physical Modifier on the Dynamical Behavior of the Polymer Composites Used in the Aviation Industry

One-pot synthesis of carbon fiber/carbon nanotube hybrid using lanthanum (III) chloride for tensile property enhancement of epoxy composites

Improved tribological properties of polyimide composites by micro–nano reinforcement

The invention discloses a graphene modified polyether ether ketone composite material and a preparation method thereof, wherein the material comprises 67-89.7% of polyether ether ketone, 0.1-1% of graphene, 0.1-1% of carbon nanotubes, 5-15% of polytetrafluoroethylene, 0.1-1% of nano-silica and 5-15% of para-polyphenol. The preparation method comprises the steps: dispersing the raw materials in anorganic solvent by ultrasound, stirring evenly to obtain powder, and followed by, carrying out hot pressing sintering of the powder. The polyether ether ketone composite material has the remarkable advantages that the polyether ether ketone composite material has good mechanical properties, good temperature resistance, stable friction coefficient and low wear rate, can effectively improve the service life and reliability of an ultrasonic motor, and can be applied to application requirements in special environments such as high and low temperatures and large load; and at the same time, the typical hot pressing sintering method only needs to be used during preparation to achieve preparation molding, the technology is simple and reliable, and the cost is low.

Graphene modified polyether ether ketone composite material and preparation method thereof

The invention provides an ultrasonic wave motor rotor surface texture and a production method thereof. The surface texture is provided with recesses, and the diameter of each recess is in a range from 200 (mu)m to 400 (mu)m, the depth of each recess is in a range from 89.77 (mu)m to 108.5 (mu)m, and the area density of each recess is in a range from 3.14% to 12.55%. The production method is characterized in that a polyimide composite material is cut into slices and polished to be a material having the roughness less than 0.1(mu)m; the forming of the surface recesses of the polished surface of the material produced by the step A is carried out by adopting a laser etching technology, and at last, the back surface of the polyimide composite material is attached to the ultrasonic motor aluminum alloy rotor surface in an adhesive manner. The surface micro-structure produced by adopting the above mentioned technical scheme is advantageous in that the production is simple and effective, the cost is low, the size is reliable, the distribution is uniform, and operation stability of an ultrasonic motor contact interface is effectively improved, and service lifetime of a rotor friction material is prolonged.

Ultrasonic wave motor rotor surface texture and production method thereof

The invention provides a rare earth and graphene oxide synergistically-modified polyimide nano composite material as well as a preparation method and application thereof. The composite material is characterized by being prepared from the following raw materials, in parts by weight: 100 parts of polyimide, 1-5 parts of a rare earth oxide, 1-5 parts of graphene oxide, and 1-5 parts of multi-walled carbon nanotubes. The preparation method comprises the following steps: uniformly mixing composite powder, pouring the uniformly-mixed powder into a mold, performing hot-pressing molding, wherein the mold pressing temperature is 360-380 DEG C, and the pressure is 10-20 MPa, performing heat preservation for 1-2 h, performing natural cooling, and performing demoulding. The composite material providedby the invention has a stable friction coefficient and an ultra-low wear rate, the preparation method is simple and convenient to operate, and the composite material has low costs and is prone to industrialized macro-preparation; and the composite material is easily processed to form a sheet to be used in a rotary ultrasonic motor, and can improve speed stability and service life of the ultrasonic motor.

Rare earth and graphene oxide synergistically-modified polyimide nano composite material as well as application and preparation method thereof

The present invention provides a method for improving ultrasonic motor stator-rotor frictional contact performances. The method comprises the steps of: pasting a layer of frictional materials at the surface of a tooth crest of a phosphor bronze stator; employing an anodic oxidation method at one surface, being in contact with the frictional materials, of an aluminium alloy rotor to form an aluminium oxide thin film with high hardness and good wear-resisting performance; and when a motor is operated, performing frictional drive of the frictional material layer and the surface of the aluminium oxide thin film to avoid generation of the tooth trap so as to improve the service life and the motion conversion efficiency of the motor. The method for improving ultrasonic motor stator-rotor frictional contact performances can improve the output moment and the motion conversion efficiency of the motor, is low in wearing rate and can greatly improve the service life of the motor.

Qiu Jinhao

Papers

Improved tribological properties of polyimide composites by micro–nano reinforcement

Graphene modified polyether ether ketone composite material and preparation method thereof

Ultrasonic wave motor rotor surface texture and production method thereof

Rare earth and graphene oxide synergistically-modified polyimide nano composite material as well as application and preparation method thereof

Method for improving ultrasonic motor stator-rotor frictional contact performances