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 ◽  
...  

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.

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1741 ◽  
Author(s):  
Jiaxiang Wu ◽  
Huaixi Wang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Yiming Mao ◽  
...  

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.


Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 421 ◽  
Author(s):  
Jun Zhang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Zhongshen Yu ◽  
Junyi Huang ◽  
...  

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.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 66 ◽  
Author(s):  
Jingyuan Zhou ◽  
Liangliang Ding ◽  
Wenhui Tang ◽  
Xianwen Ran

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.


1998 ◽  
Vol 552 ◽  
Author(s):  
Katherine C. Chen ◽  
Paul G. Kotula ◽  
Carl M. Cady ◽  
Michael E. Mauro ◽  
Dan J. Thoma

ABSTRACTA two-phase, NbCrTi alloy (bce + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature and microstructure.


2016 ◽  
Vol 19 (1) ◽  
pp. 1600350 ◽  
Author(s):  
Feng Yue Xu ◽  
Shu Bo Liu ◽  
Yuan Feng Zheng ◽  
Qing Bo Yu ◽  
Hai Fu Wang

Author(s):  
Rong Deng ◽  
Patricia Davies ◽  
Anil K. Bajaj

A fractional derivative model of dissipative effects is combined with a nonlinear elastic model to model the response of polyurethane foam in quasi-static compression tests. A system identification method is developed based on a separation of the elastic and viscoelastic parts of the response, which is possible because of symmetries in the imposed deformation timehistory. Simulations are used to evaluate the proposed identification method when noise is present in the response. The system identification technique is also applied with some success to experimental data taken from several compression experiments on two types of polyurethane foam blocks.


1976 ◽  
Vol 55 (4) ◽  
pp. 1282-1289 ◽  
Author(s):  
Malik M. Ahmad ◽  
G.W. Froning ◽  
F.B. Mather ◽  
L.L. Bashford

2010 ◽  
Vol 658 ◽  
pp. 193-196
Author(s):  
Masakazu Tane ◽  
Tae Kawashima ◽  
Keitaro Horikawa ◽  
Hidetoshi Kobayashi ◽  
Hideo Nakajima

Dynamic and quasi-static compression tests were conducted on lotus-type porous iron with porosity of about 50% using the split Hopkinson pressure bar method and universal testing machine, respectively. In the dynamic compression parallel to the pore direction, a plateau stress region appears where deformation proceeds at nearly constant stress, while the plateau stress region does not appear in the quasi-static compression. The plateau stress region is probably caused by the buckling deformation of matrix iron which occurs only in the dynamic compression. In contrast, the compression perpendicular to the orientation direction of pores exhibits no plateau-stress regions in the both dynamic and quasi-static compression.


Author(s):  
Tinard Violaine ◽  
Nguyen Quang Tam ◽  
Fond Christophe

High damping rubber (HDR) is used in HDR bearings (HDRBs) which are dissipating devices in structural systems. These devices actually have to support permanent static load in compression and potential cyclic shear when earthquakes occur. Mastering the behavior of bearings implies an accurate understanding of HDR response in such configuration. The behavior of HDR is, however, complex due to the nonlinearity and time dependance of stress–strain response and especially Mullins effect. To the authors' knowledge, tests on HDR under combined quasi-static compression and cyclic shear (QC-CS) have not been performed with regard to Mullins effect yet. The purpose of this study is thus to assess experimentally Mullins effect in HDR, especially under QC-CS. In order to achieve this aim, cyclic tensile and compression tests were first carried out to confirm the occurrence of Mullins effect in the considered HDR. Then, an original biaxial setup allowing testing HDR specimen under QC-CS was developed. This setup enables us to identify Mullins effect of the considered HDR under this kind of loading. Tests carried out with this setup were thus widened to the study of the influence of compression stress on shear response under this loading, especially in terms of shear modulus and density of energy dissipation.


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