scholarly journals Mechanical Properties and Reaction Characteristics of Al-ZrH2-PTFE Composites under Quasi-Static Compression

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 421 ◽  
Author(s):  
Jun Zhang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Zhongshen Yu ◽  
Junyi Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reaction Mechanism ◽  
High Speed ◽  
Calorific Value ◽  
Reaction Rates ◽  
Zirconium Hydride ◽  
Reaction Products ◽  
Static Compression ◽  
Reaction Characteristics ◽  
Quasi Static Compression

To analyze the mechanical properties and reaction characteristics of Al-ZrH2-PTFE (aluminum-zirconium hydride-polytetrafluoroethylene) composites under quasi-static compression, five types of specimens with different ZrH2 contents (0%, 5%, 10%, 20% and 30%) were prepared by molding-vacuum sintering. The true stress-strain curves and reaction rates of the different specimens were measured using quasi-static compression. The specific reaction processes were recorded by a high-speed camera. The corresponding reaction products were characterized by the XRD phase analysis, the calorific value was tested by a Calorimeter, and the reaction mechanism was analyzed. According to the results, the strength of the composites increased first and then decreased with the increase in the content of ZrH2. It reached a maximum of 101.01 MPa at 5%. Violent reaction occurred, and special flames were observed during the reaction of the specimens with 5% ZrH2. With the increase in the content of ZrH2, the chemical reaction was hard to induce due to the reduction in strength and toughness of composites. The reaction mechanism of Al/ZrH2/PTFE reveals that high temperatures at crack tip induced the reaction of Al and PTFE. Subsequently, ZrH2 decomposed to release hydrogen and generate ZrC. Calorimetric experiment shows that the calorific value of Al/ZrH2/PTFE with 20% ZrH2 is higher than that of Al/PTFE. The findings verify the potential of ZrH2 as an energetic additive for the enhancement of strength and release of the energy of the composites.

scholarly journals Investigation on the Thermal Behavior, Mechanical Properties and Reaction Characteristics of Al-PTFE Composites Enhanced by Ni Particle

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1741 ◽  
Author(s):  
Jiaxiang Wu ◽  
Huaixi Wang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Yiming Mao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Density ◽  
Thermal Behavior ◽  
Volume Fraction ◽  
Damage Effect ◽  
Static Compression ◽  
Hardening Modulus ◽  
Reaction Characteristics ◽  
Ptfe Composites ◽  
Quasi Static Compression

Al-PTFE (aluminum-polytetrafluoroethene) is regarded as one of the most promising reactive materials (RMs). In this work, Ni (Nickel) was added to Al-PTFE composites for the purpose of improving the energy density and damage effect. To investigate the thermal behavior, mechanical properties and reaction characteristics of the Al-Ni-PTFE composites, an Al-PTFE mixture and an Al-Ni mixture were prepared by ultrasonic mixing. Six types of Al-Ni-PTFE specimens with different component mass ratios were prepared by molding sintering. Simultaneous thermal analysis experiments were carried out to characterize the thermal behavior of the Al-PTFE mixture and the Al-Ni mixture. Quasi-static compression tests were performed to analyze the mechanical properties and reaction characteristics of the Al-Ni-PTFE specimens. The results indicate that the reaction onset temperature of Al-Ni (582.7 °C) was similar to that of Al-PTFE (587.6 °C) and that the reaction heat of Al-Ni (991.9 J/g) was 12.5 times higher than that of Al-PTFE (79.6 J/g). With the increase of Ni content, the material changed from ductile to brittle and the strain hardening modulus and compressive strength rose first and then subsequently decreased, reaching a maximum of 51.35 MPa and 111.41 MPa respectively when the volume fraction of Ni was 10%. An exothermic reaction occurred for the specimens with a Ni volume fraction no more than 10% under quasi-static compression, accompanied by the formation of Ni-Al intermetallic compounds. In the Al-Ni-PTFE system, the reaction between Al and PTFE preceded the reaction between Al and Ni and the feasibility of increasing the energy density and damage effect of the Al-Ni-PTFE reactive material by means of Ni-Al reaction was proved.

scholarly journals Effect of addition of HTa to Al/PTFE under quasi-static compression on the properties of the developed energetic composite material

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8540-8545
Author(s):  
Xinxin Ren ◽  
Yuchun Li ◽  
Junyi Huang ◽  
Jiaxiang Wu ◽  
Shuangzhang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Compression Tests ◽  
Static Compression ◽  
Reactive Materials ◽  
Reaction Characteristics ◽  
Quasi Static Compression

To study the mechanical properties and reaction characteristics of Al/HTa/PTFE reactive materials under quasi-static compression, five types of Al/HTa/PTFE specimens with different HTa contents were prepared for quasi-static compression tests.

Quasi-Static and Dynamic Compressive Behaviors of Closed-Cell Stochastic Foams Based on Voronoi Model

2019 ◽  
Author(s):  
Jianyong Chen ◽  
Jun Liu ◽  
Yuansheng Cheng ◽  
Pan Zhang
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Dynamic Compression ◽  
Voronoi Tessellation ◽  
Three Dimensional ◽  
Static Compression ◽  
Plateau Stress ◽  
Closed Cell ◽  
Collapse Mode ◽  
Quasi Static Compression

Abstract Closed-cell stochastic foams are widely used in engineering field due to the excellent energy absorption capability. In this paper, the crushing response of three dimensional closed-cell foams is investigated under quasi-static and dynamic compression loading. Voronoi tessellation is employed to generate the mesoscale geometric models of closed-cell stochastic foams, and subsequently numerical analysis is carried out using LS-DYNA software. Results reveal that the plateau stress of Voronoi model under quasi-static compression linearly increases with the increase of relative density. In addition, the mechanical properties of Voronoi model under quasi-static and dynamic compression are related to a shear band collapse mode and a layer-wise collapse mode, respectively. The plateau stress and the densification strain under high-speed loading are higher than those under quasi-static and low-speed loading.

scholarly journals Experimental Study of Mechanical Properties and Impact-Induced Reaction Characteristics of PTFE/Al/CuO Reactive Materials

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 66 ◽  
Author(s):  
Jingyuan Zhou ◽  
Liangliang Ding ◽  
Wenhui Tang ◽  
Xianwen Ran
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Sem Images ◽  
Static Compression ◽  
Drop Hammer ◽  
Reactive Materials ◽  
Reaction Characteristics ◽  
Induced Reaction

Metal/fluoropolymer materials are typical reactive materials. Polytetrafluoroethylene (PTFE)/Al/CuO reactive materials were studied in this research. Scanning electron microscopy (SEM), quasi-static compression, the Split Hopkinson pressure bar test, and the drop hammer test were used to study the mechanical properties and induced reaction characteristics of the reactive materials with different Al/CuO thermite contents and different particle sizes. SEM images of the samples demonstrate that the reactive materials were mixed evenly. The compression test results show that, if the particle size of PTFE was too small, the strength of reactive materials after sintering was reduced. After sintering, with the increase in the content of Al/CuO thermite, the strength of the micro-sized PTFE/Al/CuO firstly increased and then decreased. The Johnson–Cook constitutive model can be used to characterize the reactive materials, and the parameters of the Johnson–Cook constitutive model of No. 3 reactive materials (PTFE/Al:Al/CuO = 3:1) were obtained. The reliability of the parameters was verified by numerical simulation. Drop hammer tests show that the addition of Al/CuO aluminothermic materials or the use of nano-sized PTFE/Al reactive materials can significantly improve the sensitivity of the material. The research in this paper can provide a reference for the preparation, transportation, storage, and application of reactive materials.

scholarly journals Impact of cutting parameters on the mechanical properties of BTA deep drilled components under quasi-static compression

Procedia CIRP ◽  
2021 ◽  
Vol 103 ◽  
pp. 207-212
Author(s):  
Simon Strodick ◽  
Robert Schmidt ◽  
Lars Gerdes ◽  
Andreas Zabel ◽  
Dirk Biermann ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cutting Parameters ◽  
Static Compression ◽  
Quasi Static Compression

scholarly journals Influence of Molding Parameters on Quasi-Static Mechanical Properties of Al-Rich Al/PTFE/TiH2 Active Materials

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2750
Author(s):  
Yilei Wang ◽  
Chunlan Jiang
Keyword(s):  
Mechanical Properties ◽  
Holding Time ◽  
Molding Process ◽  
Active Materials ◽  
Static Compression ◽  
Strength Failure ◽  
Static Mechanical ◽  
Properties Of Materials ◽  
Static Mechanical Properties ◽  
Quasi Static Compression

Preforming pressure and the pressure holding time are important parameters of the molding process, which directly affect the mechanical properties of materials. In order to obtain the best molding parameters of Al-rich Al/PTFE/TiH2 composites, based on the quasi-static compression test, the influence of molding parameters on the mechanical properties of Al-rich Al/PTFE/TiH2 composites was analyzed, and the microstructure characteristics of Al-rich Al/PTFE/TiH2 specimens were analyzed by SEM. An X-ray diffractometer was used to analyze the phase of the residue after quasi-static compression experiment. The results show that: (1) With the increase in molding parameters (preforming pressure and the pressure holding time), the compressive strength, failure strain and toughness of Al-rich Al/PTFE/TiH2 specimens first increase and then decrease. The best molding process parameters of Al-rich Al/PTFE/TiH2 materials are preforming pressure 240 MPa and the pressure holding time 100 s. (2) For unsintering specimens, when the preforming pressure is less than 150 MPa, the porosity of the specimen increases slowly at first and then decreases. When the preforming pressure is greater than 150 MPa, the porosity of the specimen increases first and then decreases. When the pressure holding time is no more than 100 s, the porosity of the specimen decreases gradually. When the pressure holding time is more than 100 s, the porosity of the specimen increases first and then decreases. For sintered specimens, when the preforming pressure is less than 100 MPa, the porosity of the specimen decreases gradually. When the preforming pressure is greater than 100 MPa, the porosity of the specimen first increases and then decreases. With the increase in the pressure holding time, the porosity first increases and then decreases. For each preforming pressure specimen, compared with that before sintering, the porosity after sintering either decreases or increases. For each the pressure holding time specimen, the porosity increases after sintering compared with that before sintering. The microstructure of PTFE crystal inside the specimen is mainly planar PTFE crystal. The size and number of planar PTFE crystals are significantly affected by the molding parameters, which further affects the mechanical properties of Al-rich Al/PTFE/TiH2 specimens. When the preforming pressure is less than 100 MPa, the planar PTFE crystals are small and few, which results in the worst mechanical properties of the specimens. When the preforming pressure is more than 100 MPa and does not contain 240 Mpa, the planar PTFE crystals are small and there are more of them, which results in better mechanical properties of the specimens. When the preforming pressure is 240 MPa, the planar PTFE crystals are large and numerous, which results in the best mechanical properties of the specimen. When the pressure holding time is 100 s, the planar PTFE crystals are large and there are more of them, which results in the best mechanical properties of the specimen. (3) The reactivity of Al-rich Al/PTFE/TiH2 specimens with TiH2 the content of 10% under quasi-static compression is not significantly affected by the molding parameters.

scholarly journals The Mechanical and Reaction Behavior of PTFE/Al/Fe2O3 under Impact and Quasi-Static Compression

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jun-yi Huang ◽  
Xiang Fang ◽  
Yu-chun Li ◽  
Bin Feng ◽  
Huai-xi Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Xrd Analysis ◽  
High Speed Photography ◽  
Experimental Conditions ◽  
Static Compression ◽  
Reaction Behavior ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Quasi Static Compression

Quasi-static compression and drop-weight test were used to characterize the mechanical and reaction behavior of PTFE/Al/Fe2O3 composites. Two kinds of PTFE/Al/Fe2O3 composites were prepared with different mass of PTFE, and the reaction phenomenon and stress-strain curves were recorded; the residuals after reaction were analyzed by X-ray diffraction (XRD). The results showed that, under quasi-static compression condition, the strength of the materials is increased (from 37.1 Mpa to 77.2 Mpa) with the increase of PTFE, and the reaction phenomenon occurred only in materials with high PTFE content. XRD analysis showed that the reaction between Al and Fe2O3 was not triggered with identical experimental conditions. In drop-weight tests, PTFE/Al/Fe2O3 specimens with low PTFE content were found to be more insensitive by high-speed photography, and a High Temperature Metal Slag Spray (HTMSS) phenomenon was observed in both kinds of PTFE/Al/Fe2O3 composites, indicating the existence of thermite reaction, which was confirmed by XRD. In PTFE/Al/Fe2O3 system, the reaction between PTFE and Al precedes the reaction between Al and Fe2O3.

Tailoring Microstructures and Mechanical Properties of AlCoCrFeNiTi0.3 High-Entropy Alloys by Heat Treatment

2013 ◽  
Vol 745-746 ◽  
pp. 768-774 ◽  
Author(s):  
Jun Wei Qiao ◽  
Y.F. Wang ◽  
R.Q. Wang ◽  
J.Y. Shi ◽  
S.B. Sang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Volume Fraction ◽  
Treatment Temperature ◽  
High Entropy Alloys ◽  
Static Compression ◽  
High Entropy ◽  
Bcc Structure ◽  
Microstructures And Mechanical Properties ◽  
Quasi Static Compression

The microstructures and mechanical properties of AlCoCrFeNi0.3 high-entropy alloys (HEAs) are tailored through heat treatment. During heat treatment, the dendrite phase with a body-centered-cubic (bcc) structure transformed into the interdendrite phase with a bcc structure. Due to the element accumulation with higher hardness in the interdendrites and the increase of volume fraction of interdendrites, the average hardness of AlCoCrFeNi0.3 HEAs increased with the heat-treatment temperature, and the highest hardness was 625 HV. After 500 heat treatment, the optimized mechanical properties under quasi-static compression were achieved, and the yielding strength and fracture plasticity were 2.30 GPa and 9 %, respectively. Upon dynamic loading, the mechanical properties of HEAs were greatly enhanced.

Effect of Glass Microballoons Size on Compressive Strength of Syntactic Foams

2011 ◽  
Vol 321 ◽  
pp. 7-10 ◽  
Author(s):  
Zhuo Chen ◽  
Zhi Xiong Huang ◽  
Yan Qin ◽  
Min Xian Shi ◽  
Qi Lin Mei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Size Distribution ◽  
Syntactic Foam ◽  
Syntactic Foams ◽  
Static Compression ◽  
Distribution Ranges ◽  
Glass Microballoons ◽  
Quasi Static Compression

In this work, syntactic foams made of microballoons having same wall thickness ratio but with different particle size was prepared. Microballoons of three size distribution ranges were selected .The property of the syntactic foams were studied by quasi-static compression test. The experimental results show the microballoons size doesn’t influent the mechanical properties of the syntactic foam significantly. The failure mode of the syntactic foams was also studied in this work.

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