Core@Double-Shell Structured Energetic Composites with Reduced Sensitivity and Enhanced Mechanical Properties

2019 ◽  
Vol 11 (33) ◽  
pp. 30341-30351 ◽  
Author(s):  
Congmei Lin ◽  
Bing Huang ◽  
Feiyan Gong ◽  
Zhijian Yang ◽  
Jiahui Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energetic Composites

Litchi-like Core–Shell HMX@HPW@PDA Microparticles for Polymer-Bonded Energetic Composites with Low Sensitivity and High Mechanical Properties

2019 ◽  
Vol 12 (3) ◽  
pp. 4002-4013 ◽  
Author(s):  
Congmei Lin ◽  
Chengcheng Zeng ◽  
Yushi Wen ◽  
Feiyan Gong ◽  
Guansong He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Core Shell ◽  
Low Sensitivity ◽  
Energetic Composites

scholarly journals Enhanced Interfacial and Mechanical Properties of PBX Composites via Surface Modification on Energetic Crystals

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1308 ◽  
Author(s):  
Chengcheng Zeng ◽  
Zhijian Yang ◽  
Jianhu Zhang ◽  
Yubin Li ◽  
Congmei Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Interfacial Interaction ◽  
Polar Component ◽  
Sem Images ◽  
Polymer Binders ◽  
A Value ◽  
Polymer Bonded Explosives ◽  
Two Phases ◽  
Energetic Composites

The mechanical properties of composites are highly dependent on the interfacial interaction. In the present work, inspired by marine mussel, the adhesion between energetic crystals of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and polymer binders was improved. Three types of linear polymeric agents of glycidyl azide polymer (GAP), polyethylene glycol (PEG), and polytetramethylene ether glycol (PTMEG) were grafted onto TATB particles bridged through polydopamine (PDA) films. SEM images showed that 5% grafting contents could evidently form roughness shells on the surface. With a reinforcement at the interface produced by grafting shells, the mechanical properties of polymer-bonded explosives (PBXs) exhibited outstanding mechanical performance, especially for the PTMEG-grafting sample. Examined by the contact-angle test, the PTMEG-grafting sample possessed a value of polar component similar to that of fluoropolymer, leading to an excellent wettability of the two phases. Additionally, different contents of PTMEG were grafted to reveal that the mechanical properties could be improved even with content as little as 0.5 wt.% PTMEG. These results might highlight a correlation between interfacial interaction and macroscopic properties for mechanically energetic composites, while providing a versatile route of grafting on highly loaded composites.

scholarly journals Prediction of Effective Thermo-Mechanical Properties of Particulate Composites

2006 ◽  
Author(s):  
S. Ravi Annapragada ◽  
Dawei Sun ◽  
Suresh V. Garimella
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Energetic Materials ◽  
Particle Diameter ◽  
Heterogeneous Material ◽  
Particulate Composites ◽  
Diameter Distribution ◽  
Finite Volume Approach ◽  
Energetic Composites ◽  
Good Agreement

A micromechanics model is developed to predict the effective thermo-mechanical properties of energetic materials, which are composite materials made from agglomeration of particles of a range of sizes. A random packing algorithm is implemented to construct a representative volume element for the heterogeneous material based on the experimentally determined particle diameter distribution. The effective mechanical properties of the material are then evaluated through finite element modeling, while its thermal properties are determined through a finite volume approach. The model is first carefully validated against results from the literature and is then used to estimate the thermo-mechanical properties of particular energetic materials. Good agreement is found between experimental results and predictions. The stress-bridging phenomenon in the particulate materials is captured by the model. Thermodynamic averaging is shown to be a poor representation for the estimation of thermal properties of these heterogeneous materials. Also, the general elastic-plastic assumption is found not to be applicable for describing the mechanical behavior of energetic composites.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

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