scholarly journals Investigation of Impact Strength and Hardness of UHMW Polyethylene Composites Reinforced with Nano-Hydroxyapatite Particles Fabricated by Friction Stir Processing

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1041 ◽  
Author(s):  
Imran Khan ◽  
Ghulam Hussain ◽  
Khalid A Al-Ghamdi ◽  
Rehan Umer
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Friction Stir Processing ◽  
Volume Fraction ◽  
Polymeric Materials ◽  
Processing Parameters ◽  
Rockwell Hardness ◽  
Friction Stir ◽  
The Impact ◽  
Polyethylene Composites

The impact strength and surface properties of polymeric materials are of critical importance in various engineering applications. Friction stir processing (FSP) is a novel method for the fabrication of composite materials with superior mechanical properties. The main objective of this study is to investigate the impact strength and Rockwell hardness of UHMW polyethylene composites reinforced with nano-hydroxyapatite particles fabricated through FSP. The spindle speed (ω), tool traverse speed (f), volume fraction (v) of strengthening material and shoulder temperature (T) were key processing parameters. The analysis of variance (ANOVA) indicated that the selected processing parameters were significant. Microscopic investigations unveiled that high levels of (v, f) and low levels of (T, ω) caused agglomeration of the reinforcing particles and induced voids and channels, which consequently reduced the impact strength and hardness of the manufactured composite. However, medium conditions of processing parameters exhibited better distribution of particles with minimum defects, and hence resulted in better mechanical properties. Finally, the models to predict the impact strength and hardness are proposed and verified. Sets of process parameters favorable to maximize the impact strength and Rockwell hardness were worked out, which were believed to increase the impact strength, Rockwell hardness number, and ultimate tensile strength by 27.3%, 5.7%, and 11.2%, respectively.

Influence of the Ageing Temperature on the Selected Mechanical Properties of the Ti6Al7Nb Alloy

2015 ◽  
Vol 641 ◽  
pp. 120-123 ◽  
Author(s):  
Robert Dąbrowski ◽  
Janusz Krawczyk ◽  
Edyta Rożniata
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Volume Fraction ◽  
Heating Temperature ◽  
Ageing Temperature ◽  
Sample Length ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase ◽  
The Impact

The results of investigations of the influence of the ageing temperature on the selected mechanical properties i.e. hardness, fracture toughness (examined by the linear elastic fracture mechanics - KIctest) and impact strength (KV) of two-phase Ti6Al7Nb alloy, are presented in the hereby paper. Investigations were performed in the ageing temperatures range: 450÷650°C of the alloy previously undercooled from the selected heating temperature (in two-phase range) - equal 970°C. The heating temperature was determined on the basis of the dilatometric curve of the alloy heating in the system ΔL = f ((T), where: ΔL – change of the sample length, T – temperature, which was then differentiated in the system: ΔL/ΔT = f (T). The dilatometer L78 R.I.T.A of the LINSEIS Company was used in the tests. Investigations of the alloy microstructure in the ageing temperatures range 450÷650°C were carried out by means of the light microscope Axiovert 200 MAT of the Carl Zeiss Company. It was found that nearly equiaxial grains of the primary α phase occur in the microstructure (of the volume fraction app. 30%) and that the volume fraction of the new lamellar α phase - formed from the supersaturated β phase - increases. With an increase of the alloy ageing temperature, in the mentioned above range, a small increase of its hardness from 305 to 324HV as well as a decrease of stress intensity factor KIcfrom 67.3 to 48.6 MPa x m1/2and impact strength (KV) from 40.2 to 31.3 J. The impact tests results were supplemented by the fractographic documentation. It was found, that the characteristic features of the fractures of impact test samples do not exhibit essential differences in dependence of the ageing temperature and material hardness. The fractographic investigations were performed by means of the scanning electron microscope NovaNanoSEM 450.

scholarly journals Effects of the Processing Parameters of Friction Stir Processing on the Microstructure, Hardness and Tribological Properties of SnSbCu Bearing Alloy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5826
Author(s):  
Beata Leszczyńska-Madej ◽  
Marcin Madej ◽  
Joanna Hrabia-Wiśnios ◽  
Aleksandra Węglowska
Keyword(s):  
Tribological Properties ◽  
Friction Stir Processing ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Friction Stir ◽  
Modification Process ◽  
Hardness Tests ◽  
Before And After ◽  
Bearing Alloy ◽  
The Impact

In the study, the friction stir processing (FSP) method was used to modify the surface layer of a tin-based bearing alloy. The modification was aimed at extending the service life of bearings by improving their tribological properties. The results of investigations of the microstructure, hardness and tribological properties of the SnSbCu bearing alloy after FSP using various rotational speeds of the tool—280, 355, 450 and 560 RPM—and the constant traverse speed of 355 mm/min are presented. Particular attention was paid to the possibility of changing the morphology of the precipitates present in the alloy, and to the impact of this parameter on improvement of the tribological properties. The research carried out in this paper covered investigations of the microstructure using light and scanning electron microscopy (SEM) along with analysis of the chemical composition in micro-areas and Brinell hardness tests. Additionally, the sizes of the SnSb and CuSn precipitates present in the microstructure before and after the modification process were determined, as were the tribological properties under technically dry friction conditions and lubrication with TU 32 oil. It was proven that using friction stir processing favors refinement of the microstructure and improves the tribological properties of the analyzed alloy.

Effects of Processing Parameters and Nanofillers on Mechanical and Thermal Properties and Morphology of Impact Modified Poly (lactic acid)

2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Impact Strength ◽  
Random Copolymer ◽  
Processing Parameters ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Injection Molded ◽  
The Impact

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.

scholarly journals PENGARUH FRAKSI VOLUME SERAT TERHADAP SIFAT MEKANIS KOMPOSIT MATRIKS POLIMER POLYESTER DIPERKUAT SERAT AGAVE SISAL

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Gede Aprianto ◽  
I Nyoman Pasek Nugraha ◽  
Kadek Rihendra Dantes
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Repeated Measures ◽  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Repeated Measures Design ◽  
Pull Out ◽  
The Impact

Penelitian ini bertujuan untuk mengetahui fraksi volume terbaik dari sifat mekanik komposit matriks polimer polyester yang diperkuat serat alam agave sisal. Sifat mekanik yang dimaksud adalah kekuatan impak dan mikrografi. Desain penelitian yang digunakan dalam penelitian ini adalah penelitian eksperimen dengan metode single factor repeated measures design. Pembuatan sampel komposit matriks polimer polyester yang diperkuat serat alam agave sisal menggunakan metode hand lay up. Variasi fraksi volume serat yang digunakan adalah 0%, 20%, 40%, dan 60%. Setiap fraksi volume serat yang diuji, dibuatkan masing-masing 10 (sepuluh) buah spesimen. Data-data yang diperoleh dalam penelitian ini di dapat dari energi serap (Es) pengujian impak yang selanjutnya diolah dan dianalisa menggunakan Anava As. Hasil penelitian menunjukkan bahwa : (1) Fraksi volume serat terbaik dalam pengujian impak adalah fraksi volume serat 40% dengan kekuatan impak sebesar 4.092,00818 J/m2, sedangkan fraksi volume serat terendah adalah fraksi volume serat 0% dengan kekuatan impak sebesar 604,50120 J/m2; (2) Berdasarkan hasil pengujian mikrografi dari patahan hasil pengujian impak menunjukkan bahwa secara umum pola patahan yang terjadi pada komposit adalah kombinasi dari patahan getas (brittle fracture) dan pull-out fibers fracture atau dikenal dengan patahan sikat (brush fracture). Kesimpulan dari penelitian ini adalah fraksi volume serat 40% memiliki sifat mekanik terbaik dibandingkan dengan fraksi volume serat lainnya sehingga dapat dijadikan sebagai salah satu bahan baku alternatif pengganti serat gelas, dimana kekuatan impak yang dihasilkan sebesar 4.092,00818 J/m2. Dilihat dari hasil pengujian mikrografi, secara umum dikategorikan memiliki pola patahan sikat (brush fracture).Kata Kunci : komposit, matriks polimer polyester, serat alam agave sisal, sifat mekanis This research aims to know the best fiber volume fraction on mechanical properties of agave sisal natural fiber which is reinforced by polyester matrix composites. Those mechanical properties are the impact strength and the micrographic. The research design used in this research is an experimental research with single factor repeated measures design method. The manufacture of agave sisal natural fiber which is reinforced by polyester matrix composites specimens used hand lay-up methods. The variations of the fiber volume fraction used were 0%, 20%, 40% and 60%. There are 10 (ten) pieces of specimens for each tested fiber volume fraction. The research data was obtained from specimens absorbed energy (Es). Then, they were processed and analyzed by using Anova As. The result of this research showed that: (1) the best fiber volume fraction during impact testing is 40% with 4.092,00818 J/m2 of the impact strength. Meanwhile, the worst fiber volume fraction is 0% with 604,50120 J/m2 of the impact strength; (2) based on the micrographic test, the fractures from the impact test showed that the pattern of those fractures generally consists the combination of brittle fractures and pull-out fiber fractures. This combination is known as brush fractures. The conclusion of this research is the 40% of fiber volume fraction has the best mechanical properties compared to the other fiber volume fraction. Thus, it can be used as the alternative raw material for fiberglass. The impact strength produced was 4.092,00818 J/m2. Based from the micrographic test, the fraction is categorized as the brush fractures pattern.keyword : agave sisal natural fiber, composite, material properties, polyester polymer matrix

Multicriteria optimization of mechanical properties of aluminum composites reinforced with different reinforcing particles type

2017 ◽  
Vol 232 (3) ◽  
pp. 323-337 ◽  
Author(s):  
Mostafa Akbari ◽  
Parviz Asadi ◽  
Parisa Zolghadr ◽  
Abolfazl Khalkhali
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Processing ◽  
Processing Parameters ◽  
Pareto Optimal ◽  
Aluminum Composites ◽  
Nsga Ii ◽  
Friction Stir ◽  
Reinforcing Particles ◽  
Pareto Optimal Set ◽  
Optimal Set

In this investigation, the mechanical and microstructural properties of aluminum composites reinforced by different reinforcing particles including SiC, TiC, ZrO2, and B4C were optimized using neural network and NSGA-II. In order to obtain the best microstructural and mechanical properties of aluminum composites, different friction stir processing parameters such as rotational and traverse speed and different reinforcing particles type were used in order to fabricate composites. Results show that friction stir processing significantly affect Si particles size as well as dispersion and fraction of reinforcing particles at the stir zone. Moreover, reinforcing particle types influence the mechanical properties of composites due to difference in hardness and thermal expansion of each reinforcement as well as bonding quality between each reinforcement and aluminum matrix. In order to model the correlation between the friction stir processing parameters and microstructural and mechanical properties of the composites, an artificial neural network model was developed. A modified NSGA-II by incorporating diversity preserving mechanism called the ɛ elimination algorithm was employed to obtain the Pareto-optimal set of friction stir processing parameters. Finally, an approach based on TOPSIS method was applied for determining the best compromised solution from the obtained Pareto-optimal set.

Influence of the Porous Volume in the Structure of Resin Bond Composite Abrasives by its Mechanical Performance

2020 ◽  
Author(s):  
Matheus de Mendonça Chitan ◽  
Katia Cristiane Gandolpho Candioto
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Low Cost ◽  
Polymeric Materials ◽  
Porous Volume ◽  
The Impact

Abstract Abrasive tools consist of abrasive grains, binder and pores. Binders are the matrix of the material and may be of the metallic, vitrified or resin type. The wide use of polymeric materials (resinoid) is due to their low cost and excellent mechanical properties. The grain has the function of roughing the material, the binder, on the other hand, has the characteristics of ensuring grain adhesion and the pores in the structure are responsible for cooling the abrasive tool. In this work, we report the preparation and evaluation of the mechanical characteristics of resin bond composite abrasives with different structures based on the porous concentration. The composite abrasives were made with phenolic resin and alumina grains. Four different structures were studied from 10 to 30% of porous volume fraction with 50% of grain volume fraction. The concentration of porous and bond in the structure composition were employed to compare the mechanical performance of the prepared composite abrasive. To evaluate the mechanical properties of composites, Impact strength, Young’s Modulus by impulse excitation and flexural strength were realized. It was observed that as the porosity is higher, the impact resistance (absorbed energy) is lower, which confirms the lower resistance produced by the surface area contact (grain/binder) and a greater accumulation of tension in the binder material, the higher porosity value, higher the flexural strength value until 20% of porosity. Samples with higher volumes level of porosity presented lower Young’s Modulus but the presence of pores produced by volatiles by-products (mainly water) should act as stress concentrators, thus favoring lower mechanical properties at the resin-grain interface.

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