scholarly journals Enhancing the Mechanical and Tribological Properties of Cellulose Nanocomposites with Aluminum Nanoadditives

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1246
Author(s):  
Shih-Chen Shi ◽  
Tao-Hsing Chen ◽  
Pramod Kumar Mandal
Keyword(s):  
Tensile Strength ◽  
Load Capacity ◽  
Hydroxypropyl Methylcellulose ◽  
Base Material ◽  
Wear Test ◽  
Barrier Properties ◽  
Wear Volume ◽  
Mechanical And Tribological Properties ◽  
The Matrix ◽  
Tribology Performance

Hydroxypropyl methylcellulose (HPMC) is a common hydrophilic and biodegradable polymer that can form films. This study incorporated aluminum nanoadditives as an enhancement reagent into a HPMC matrix. Mechanical properties of nanocompoistes, including the tensile strength and the elastic modulus, were analyzed with a nano-tensile tester. The incorporation of additives in HPMC films significantly enhances their mechanical and film barrier properties. Evidence of bonding between the additive and matrix was observed by Fourier-transform infrared spectrometer analysis. The additives occupy the spaces in the pores of the matrix, which increases the tendency of the pore to collapse and improves the chemical bonding between the base material and the additives. The incorporation of excess additives decreases the tensile strength due to ineffective collisions between the additives and the matrix. The wear test proves that the addition of nano-additives can improve the tribology performance of the HPMC composite while reducing the wear volume and the friction. Bonding between the nanoadditives and the matrix does not help release the nanoadditives into the wear interface as a third-body layer. The main reason to enhance the tribology performance is that the nanoadditives improve the load-capacity of the composite coating. This hybrid composite can be useful in many sustainability applications.

Processing Routes, Mechanical, and Tribological Properties of Light Metal Matrix Nanocomposites

2017 ◽  
pp. 991-1037
Author(s):  
S. Jayalakshmi ◽  
R. Arvind Singh
Keyword(s):  
Tribological Properties ◽  
Metal Matrix ◽  
Base Material ◽  
Light Metal ◽  
Advanced Materials ◽  
Matrix Composites ◽  
Metal Matrix Nanocomposites ◽  
Mechanical And Tribological Properties ◽  
The Matrix ◽  
Matrix Nanocomposites

The chapter highlights the various processing/synthesizing routes of Light Metal Matrix Nanocomposites (LMMNCs), their microstructural characteristics, mechanical behaviour, and tribological properties. LMMNCs are advanced materials, in which nano-sized ceramic particles are reinforced into Al/Mg matrices. In conventional Metal Matrix Composites (MMCs), the incorporation of micron sized reinforcements in the matrix usually results in a considerable improvement in hardness and ultimate strength when compared to the unreinforced base material. However, most of these composites do not show plastic deformation (little or no yield) and exhibit drastic reduction in ductility. This poses a major limitation for MMCs to be used in real-time applications. In order to overcome this drawback, Al/Mg composites with nano-scale reinforcements have been developed. Based on numerous research works, it has been established that LMMNCs are better materials that possess superior properties, wherein both strength and ductility improvements along with excellent wear resistance can be achieved.

Assessing the Feasibility of Micro-Plasma Technology for Additive Manufacturing

2018 ◽  
Author(s):  
Jason Nagy ◽  
Xiao Huang
Keyword(s):  
Tensile Strength ◽  
Additive Manufacturing ◽  
Microstructural Analysis ◽  
Wear Test ◽  
Tensile Tests ◽  
Wear Volume ◽  
Plasma System ◽  
Weld Deposit ◽  
Feed Mode ◽  
Wire Feed

In this research, a micro-plasma system was investigated for its capability in additive manufacturing (AM). Micro-plasma AM system has the advantage of lower cost and higher deposition rate over laser based AM systems, and generates leaner and cleaner weld deposit than other arc based AM systems. However, the micro-plasma system is complex and involves a large number of process variables. In this study, the feasibility of using a micro-plasma system for additive manufacturing was assessed based on surface features, mechanical properties and microstructure. In addition, two arc and wire feed modes were examined to understand the effects of these two variables. Each was used to produce IN 718 superalloy samples for macro- and microstructure evaluation, hardness, wear, and tensile tests along both long and transverse directions. Preliminary results showed that crack free samples, measured up to 100 mm × 40 mm, can be generated without measurable distortion. Some surface discoloration was observed, ranging from light straw to a purple tint. After heat treatment, the hardness of the samples varies from 403 to 440 HV, with the transverse surface showing slightly lower hardness values. Pin-on-disk wear test yielded consistent wear volume for three sets of the samples produced using different process parameters; however, samples produced with no modifications to the current and wire feed mode showed marginally higher wear rate. Microstructural analysis with SEM and EDS revealed presence of small pinholes, measured from submicron up to 22 μm in diameter, and no indication of any cracks or boundary layers between passes. SEM analysis revealed the presence of high contrast Nb/Mo rich carbides along with γ″-Ni3Nb in the γ matrix. Finally, tensile test was carried out to understand the anisotropic behavior; the results showed that transverse direction had lower tensile strength and ductility. Samples produced with pulsed current and wire feed mode had lower yield/tensile strength but higher ductility than that without current and wire feed mode modification.

Effect of Liquid Phase during Sintering on Mechanical and Tribological Properties of Self-Lubricating Composites

2017 ◽  
Vol 899 ◽  
pp. 523-527 ◽  
Author(s):  
Renata Steinbach ◽  
Tatiana Bendo ◽  
G. Hammes ◽  
C. Binder ◽  
J.D.B. de Mello ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Liquid Phase ◽  
Friction Coefficient ◽  
High Performance ◽  
Hexagonal Boron Nitride ◽  
Solid Lubricants ◽  
Liquid Phase Sintering ◽  
Mechanical And Tribological Properties ◽  
The Matrix ◽  
Self Lubricating Composites

The present work aimed to contribute to the development of high performance self-lubricating sintered composites, with low friction coefficient and high mechanical strength. Self-lubricating composites presenting embedded solid lubricants in a ferrous matrix were produced. Hexagonal boron nitride (hBN) and graphite were the solid lubricants powders added during the mixing step. The composites were processed by conventional powder metallurgy. The liquid phase sintering, by adding copper, improved the degree of continuity of the matrix by rearranging the solid lubricant particles. With this, besides the hardening effect on the matrix, the mechanical properties of the composites were improved, with tensile strength increasing when compared to the same composite without copper. By using the proposed methodologies, optimized composites presenting friction coefficient of 0.12, tensile strength of 500 MPa and scuffing resistance of 29300 N.m were obtained.

scholarly journals Development of extended-release formulation of domperidone using a blend of Raphia hookeri gum and hydroxypropyl methylcellulose as tablet matrix

2017 ◽  
Vol 16 (10) ◽  
pp. 2341-2347
Author(s):  
Emmanuel O. Olorunsola ◽  
Stephen O. Majekodunmi
Keyword(s):  
Tensile Strength ◽  
Drug Release ◽  
Extended Release ◽  
Hydroxypropyl Methylcellulose ◽  
Direct Compression ◽  
Release Formulation ◽  
Extended Release Formulation ◽  
Raphia Hookeri ◽  
The Matrix ◽  
The Individual

Purpose: To develop an extended-release formulation of domperidone using a blend of Raphia hookeri gum and hydroxypropyl methylcellulose as tablet matrix.Methods: Tablets (400 mg) containing 30 mg domperidone (DPD) were formulated using binary mixtures of hydroxypropyl methylcellulose (HPMC) and Raphia hookeri gum (RHG) as matrix former; and microcrystalline cellulose (MCC) as direct compression excipient. The proportions of the matrix formers (40 % of tablet weight) was varied as 100:0, 75:25, 50:50, 25:75 and 0:100. The composition of the matrix former was also kept constant (50:50) while MCC was varied as 40, 30, 20 and 10 %. The tablets were evaluated for compact density, tensile strength, friability and drug release over 24 h.Results: The tensile strength of tablets decreased while their friability increased with increase in the proportion of RHG. A similar trend was observed with decrease in the concentration of MCC. Tablets containing RHG alone as matrix former and 40 % MCC as direct compression excipient had tensile strength of 0.95 MNm-2, friability of 1.07 % and cumulative drug release of 83.2 % over a period of 24 h. Tablets containing equal proportions of HPMC and RHG as matrix former had the best release properties of 95.0 % over a period of 24 h.Conclusion: RHG is comparable with HPMC in terms of extending the release of  domperidone for a once daily administration. A suitable combination of the two  polymers for use as a matrix former is superior to either of the individual polymers.Keywords: Domperidone, Extended drug release, Hydroxypropyl methylcellulose, Raphia hookeri gum, Tablet properties

Processing Routes, Mechanical, and Tribological Properties of Light Metal Matrix Nanocomposites

2015 ◽  
pp. 1-46
Author(s):  
S. Jayalakshmi ◽  
R. Arvind Singh
Keyword(s):  
Tribological Properties ◽  
Metal Matrix ◽  
Base Material ◽  
Light Metal ◽  
Advanced Materials ◽  
Matrix Composites ◽  
Metal Matrix Nanocomposites ◽  
Mechanical And Tribological Properties ◽  
The Matrix ◽  
Matrix Nanocomposites

The chapter highlights the various processing/synthesizing routes of Light Metal Matrix Nanocomposites (LMMNCs), their microstructural characteristics, mechanical behaviour, and tribological properties. LMMNCs are advanced materials, in which nano-sized ceramic particles are reinforced into Al/Mg matrices. In conventional Metal Matrix Composites (MMCs), the incorporation of micron sized reinforcements in the matrix usually results in a considerable improvement in hardness and ultimate strength when compared to the unreinforced base material. However, most of these composites do not show plastic deformation (little or no yield) and exhibit drastic reduction in ductility. This poses a major limitation for MMCs to be used in real-time applications. In order to overcome this drawback, Al/Mg composites with nano-scale reinforcements have been developed. Based on numerous research works, it has been established that LMMNCs are better materials that possess superior properties, wherein both strength and ductility improvements along with excellent wear resistance can be achieved.

scholarly journals Effect of thickness and matrix variability on properties of a starch-based nanocomposite supple film

Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 416-422
Author(s):  
A. Fadeyibi ◽  
Z.D. Osunde
Keyword(s):  
Tensile Strength ◽  
Nanocomposite Film ◽  
Barrier Properties ◽  
Cassava Starch ◽  
Mechanical And Thermal Properties ◽  
Glycerol Concentration ◽  
Zinc Nanoparticles ◽  
Reduced Modulus ◽  
The Matrix ◽  
Desirability Index

In this research, the effects of matrix variability and thickness on the properties of a flexible nanocomposite film were investigated. The nanocomposite film was prepared from the blends of 1 kg cassava starch, 45–55% (w/v) glycerol and 0–2% (w/v) zincnanoparticles in thickness ranging from 15 −17 µm. The barrier, mechanical, and thermal properties were determined experimentally. The optimal effects of the thickness and the matrix variability on the properties were determined using Response Surface Methodology. Results showed that the barrier properties increased with glycerol concentration but decreased with thickness. Reduced modulus and tensile strength increased with an increase in the matrix variability. The film was thermally stable up to 60.43oC with only 2% degradation. The optimal film contains 55% glycerol, 2% zinc nanoparticles with a thickness of 17 µm at a desirability index of 0.95. This can therefore be essential for industrial application

Investigation on Mechanical and Tribological Properties of AA7075 Alloy with B4C, Gr and Fly Ash Reinforced Hybrid Composites

2020 ◽  
Vol 979 ◽  
pp. 52-57
Author(s):  
P Azhagarsamy ◽  
K. Sekar
Keyword(s):  
Fly Ash ◽  
Hybrid Composites ◽  
Casting Machine ◽  
Wear Test ◽  
Stir Casting ◽  
Al Alloy ◽  
Test Results ◽  
Mechanical And Tribological Properties ◽  
The Matrix ◽  
Al 7075

The Aluminum alloys and its composites are used in the aerospace, automobile and marine industries due to their higher strength, stiffness and wear resistance properties. This study is focused on mechanical and tribological study of Al 7075 hybrid composite reinforced with B4C, Gr and Fly ash. The reinforcements are added to Al alloy in three different compositions such as (4wt% B4C/4wt% Gr/7wt% Fly ash, 4wt% B4C/5wt% Gr/8wt% Fly ash and 4wt% B4C/6wt% Gr/9wt% Fly ash). The stir casting machine was used for manufacturing hybrid composites. Hardness and wear tests were conducted for three different Al 7075 hybrid composites. The microstructure showed that the reinforcement was uniformly distributed in the matrix without agglomeration. The hardness and wear test results revealed that the composite with 4wt% B4C /6wt% Gr/9wt% Fly ash exhibited an increase in hardness value of about 22.69% and the minimum wear rate as compared to other composites.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

Mechanical characterization of LM25 alloy matrix composite reinforced with boron carbide

2021 ◽  
pp. 002199832110055
Author(s):  
Zeeshan Ahmad ◽  
Sabah Khan
Keyword(s):  
Tensile Strength ◽  
Boron Carbide ◽  
Mechanical Characterization ◽  
Stir Casting ◽  
Surface Mapping ◽  
Alloy Matrix ◽  
Casting Technique ◽  
The Matrix ◽  
Carbide Particles

Alumnium alloy LM 25 based composites reinforced with boron carbide at different weight fractions of 4%, 8%, and 12% were fabricated by stir casting technique. The microstructures and morphology of the fabricated composites were studied by scanning electron microscopy and energy dispersive spectroscopy. Elemental mapping of all fabricated composites were done to demonstrate the elements present in the matrix and fabricated composites. The results of microstructural analyses reveal homogenous dispersion of reinforcement particles in the matrix with some little amount of clustering found in composites reinforced with 12% wt. of boron carbide. The mechanical characterization is done for both alloy LM 25 and all fabricated composites based on hardness and tensile strength. The hardness increased from 13.6% to 21.31% and tensile strength 6.4% to 22.8% as reinforcement percentage of boron carbide particles increased from 0% to 12% wt. A fractured surface mapping was also done for all composites.

Microstructure and physical properties of composite nonwovens produced by incorporating cotton fibers in elastic spunbond and meltblown webs for medical textiles

2021 ◽  
pp. 152808372110042
Author(s):  
Partha Sikdar ◽  
Gajanan S Bhat ◽  
Doug Hinchliff ◽  
Shafiqul Islam ◽  
Brian Condon
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Barrier Properties ◽  
Cotton Fibers ◽  
Adult Care ◽  
Medical Textiles ◽  
Improved Performance

The objective of this research was to produce elastomeric nonwovens containing cotton by the combination of appropriate process. Such nonwovens are in demand for use in several healthcare, baby care, and adult care products that require stretchability, comfort, and barrier properties. Meltblown fabrics have very high surface area due to microfibers and have good absorbency, permeability, and barrier properties. Spunbonding is the most economical process to produce nonwovens with good strength and physical properties with relatively larger diameter fibers. Incorporating cotton fibers into elastomeric nonwovens can enhance the performance of products, such as absorbency and comfort. There has not been any study yet to use such novel approaches to produce elastomeric cotton fiber nonwovens. A hydroentangling process was used to integrate cotton fibers into produced elastomeric spunbond and meltblown nonwovens. The laminated web structures produced by various combinations were evaluated for their physical properties such as weight, thickness, air permeability, pore size, tensile strength, and especially the stretch recovery. Incorporating cotton into elastic webs resulted in composite structures with improved moisture absorbency (250%-800%) as well as good breathability and elastic properties. The results also show that incorporating cotton can significantly increase tensile strength with improved spontaneous recovery from stretch even after the 5th cycle. Results from the experiments demonstrate that such composite webs with improved performance properties can be produced by commercially used processes.

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