scholarly journals Enhancement Research on Piezoelectric Performance of Electrospun PVDF Fiber Membranes with Inorganic Reinforced Materials

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1495
Author(s):  
Chong Li ◽  
Haoyu Wang ◽  
Xiao Yan ◽  
Hanxige Chen ◽  
Yudong Fu ◽  
...  

The electrospun PVDF fiber membranes with the characteristics of light weight, strong signal and measurability, have been widely applied in the fields of environment, energy sensors and biomedical treatment. Due to the weakness of the piezoelectric and service properties, the conventional PVDF fiber membranes cannot meet the operating requirements. Based on the obtained optimal technological parameter of electrospun pure PVDF fiber membranes (P-PVDF) in the previous experiment (unpublished), three inorganic reinforced substances (AgNO3, FeCl3·6H2O, nanographene) were respectively used to dope and modify PVDF to prepare composite fiber membranes with the better piezoelectric performance. The morphology and crystal structure of the hybrid fiber membranes were observed and detected by scanning electron microscopy and X-ray diffraction, respectively. The results showed that the dopant could effectively promote the formation of β-phase, which can enhance the piezoelectric performance. The mechanical properties test and piezoelectric performance test exhibited that the static flexural strength, the elastic modulus, and the piezoelectric performance were improved with the addition of dopant. In addition, the influence on the addition of dopant and the doping modification mechanism were discussed. Finally, the conclusions showed that the minimum average diameter was obtained with the 0.3 wt% addition of AgNO3; the piezoelectric performance reached the strongest with the 0.8 wt% addition of FeCl3·6H2O; the mechanical properties were best with the 1.0 wt% addition of nanographene.

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jin-gang Jiang ◽  
Zhao Wang ◽  
Hong-wei Duan ◽  
Jing-qiang Liu ◽  
Xiao-wei Guo

On the basis of the finite element calculation theory of electric field, the electric field distribution in a representative electrospinning device is computed. The electric field structure of a needle-plate type electrospinning device was simulated by means of ANSYS software. And the vector distribution of the nozzle on the spinneret pipe was got. For the purpose of the analysis on the influence of different solvent ratios on the performance of a single electrospun PVDF/PEI composite film, polyvinylidene fluoride and polyetherimide with a mass ratio of 8/2 were dissolved in a mixed solvent. The mixed solvent is composed of N,N-dimethylformamide and tetrahydrofuran, added in different proportions. Through the electrostatic spinning technology, PVDF/PEI composite fiber membranes were prepared. Using scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and mechanical properties testing, the effects of tetrahydrofuran on the composite microstructure, crystallinity, and mechanical properties of the PVDF/PEI composite fiber membranes are discussed.


2011 ◽  
Vol 172-174 ◽  
pp. 190-195 ◽  
Author(s):  
Giorgia T. Aleixo ◽  
Eder S.N. Lopes ◽  
Rodrigo Contieri ◽  
Alessandra Cremasco ◽  
Conrado Ramos Moreira Afonso ◽  
...  

Ti-based alloys present unique properties and hence, are employed in several industrial segments. Among Ti alloys, β type alloys form one of the most versatile classes of materials in relation to processing, microstructure and mechanical properties. It is well known that heat treatment of Ti alloys plays an important role in determining their microstructure and mechanical behavior. The aim of this work is to analyze microstructure and phases formed during cooling of β Ti-Nb-Sn alloy through different cooling rates. Initially, samples of Ti-Nb-Sn system were prepared through arc melting furnace. After, they were subjected to continuous cooling experiments to evaluate conditions for obtaining metastable phases. Microstructure analysis, differential scanning calorimetry and X-ray diffraction were performed in order to evaluate phase transformations. Depending on the cooling rate and composition, α” martensite, ω phase and β phase were obtained. Elastic modulus has been found to decrease as the amount of Sn was increased.


2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength


2018 ◽  
Vol 884 ◽  
pp. 36-42
Author(s):  
Carlos Romero ◽  
Fei Yang ◽  
Leandro Bolzoni

Vacuum-sintered billets of Ti-6Al-4V alloy from powder blend were extruded at two different temperatures: 1150 °C and 950 °C. The extruded material at 1150 °C was subjected to various heat treatments to obtain different microstructures: annealing in the β phase, β solution treatment and aging and α+β solution treatment and aging. The materials processed were characterised using scanning electron microscopy, X-ray diffraction and the mechanical properties were measured by tensile test. The microstructure of both extrusions are fairly similar, consisting of lamellar colonies, and the mechanical properties are also comparable, with yield strengths of about 1000 MPa, ultimate tensile strength of about 1100 MPa and elongation at fracture of 8-9%. The β annealing treatment, through coarsening the lamellar microstructure, reduces the strength of the alloy while keeping a high ductility. Both solution treatments and aging, which produces aged martensite and aged martensite and primary alpha, respectively, increases the strength and reduces the ductility. There is a trade-off between ductility and strength when it comes to tailoring the microstructure, and the as-extruded Ti-6Al-4V condition is the one with the best balance between strength and ductility.


2019 ◽  
Vol 946 ◽  
pp. 287-292
Author(s):  
Alexander Thoemmes ◽  
Ivan V. Ivanov ◽  
Alexey Ruktuev

The effect of Nb content on microstructure, mechanical properties and phase formation in as-melt and annealed binary Ti-Nb alloys were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. The content of Nb varied in the range 25-35 mass % leading to significant changes in the microstructure. The annealed and furnace-cooled binary Ti-Nb samples exhibited HCP martensitic α` phase at a Nb content below 27.5 mass % and metastable BCC β phase at higher contents of Nb. The mechanical properties of alloys depended strongly on the Nb content and type of the dominating phase.


2018 ◽  
Vol 769 ◽  
pp. 29-34 ◽  
Author(s):  
Alexander Thoemmes ◽  
Ivan V. Ivanov ◽  
Adelya A. Kashimbetova

The effect of Nb content on microstructure, mechanical properties and phase formation in annealed and quenched binary Ti-Nb alloys were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. The content of Nb varied in the range 0-37 mass % leading to significant changes in the microstructure. The annealed and furnace-cooled binary Ti-Nb samples exhibited HCP martensitic α` phase at a Nb content below 14 mass % and stable BCC β phase at higher contents of Nb. The structure of the quenched samples changed with increase of Nb content in the following order: coarse primary martensite → fine acicular (α`+α``) martensite → single β phase structure. The mechanical properties of alloys strongly depended on the Nb content and type of the dominating phase.


2015 ◽  
Vol 815 ◽  
pp. 297-300 ◽  
Author(s):  
Xing Ping Fan ◽  
Ben Ju Wang ◽  
Xiao Qing Ren ◽  
Fu Chang Peng

The medical Ti-20Mo alloys were fabricated by powder metallurgy. The effects of sintering temperature on the phase, the morphology and the mechanical properties of Ti-Mo alloys were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical properties test methods. The results showed that after sintering at 1200 °C, the microstructure of Ti-Mo alloys mainly consisted of α phase. The increasing sintering time could promote α→β phase transition, thus the flexural strength and the elastic modulus of Ti-Mo alloys could be controlled. When the sintering temperature was 1300 °C, molybdenum content was 20%, the bending strength and the compressive strength of Ti-20Mo alloy were 1369MPa and 2602MPa respectively, and the elastic modulus was 3.4GPa. It may be concluded that the Ti-20Mo alloys is prospective prostheses materials.


2014 ◽  
Vol 881-883 ◽  
pp. 867-871
Author(s):  
Ji Fang Lu ◽  
Zhao Hui Zhang ◽  
Fu Chi Wang

In this paper, in situ TiB reinforced Ti-3Al, Ti-6Al and Ti-6Al-4V matrix composites were prepared by arc-melting technique utilizing the reaction between Ti and TiB2, and then forged in the α+β phase field. Phase identification was carried out via X-ray diffraction. Microstructure of the composites was studied by optical microscopy (OM) and scanning electron microscopy (SEM). Mechanical properties of the composites after forging were measured at various temperatures by tensile experiment. The results showed that Ti-6Al-4V-2TiB composite exhibits fine equiaxed matrix microstructure with a grain size of 5-10μm. The tensile strength and elongation of the composite at room temperature reached 1069MPa and 10.0%, respectively.


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 976 ◽  
Author(s):  
Qingxuan Sui ◽  
Peizhen Li ◽  
Kunlun Wang ◽  
Xiaotian Yin ◽  
Lingyu Liu ◽  
...  

Ti-6Al-4V alloys with different build orientations have been fabricated by selective laser melting (SLM). The corrosion behavior and mechanical properties have been studied. Investigation of microstructures were characterized by optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Electrochemical results show that the vertical sample and horizontal sample possess excellent corrosion resistance in the cross section and longitudinal section respectively, which can be attributed to the presence of less acicular α′ martensite and more β phase. Mechanical properties of all samples were determined by compression testing and hardness measurements. The compression strength (σc) and plastic deformation (εp) of the horizontal sample were higher than those of the vertical sample and the sample with building direction of 45°, because the molten pool boundaries (MPBs) play a significant role in the microscopic slipping at the loading SLM parts. In addition, the sample with building orientation of 45° achieved highest hardness. Therefore, distinct anisotropy due to different build orientations.


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