An investigation into the wear behaviour of TiB2 particle reinforced aluminium composites produced by mechanical alloying

2011 ◽  
Vol 18 (1-2) ◽  
pp. 5-12 ◽  
Author(s):  
Dursun Ozyurek ◽  
Ibrahim Ciftci
Keyword(s):  
Mechanical Alloying ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
A356 Alloy ◽  
Tib2 Particle ◽  
Wear Behaviour ◽  
Wear Loss ◽  
Mechanically Alloyed ◽  
Particle Volume ◽  
Alloy Matrix

AbstractIn this study, wear behaviour of TiB2 particle reinforced aluminium (Al) composites produced by the mechanical alloying method was investigated. TiB2 ceramic particles of four different volume fractions were mechanically alloyed with Al and A356 alloy matrix materials. The mechanically alloyed particles were cold presses and then sintered at 550°C. After the sintering process, the composites were characterised through hardness measurements, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Wear tests were also carried out on a pin-on-disc type wear apparatus under 10, 25 and 50 N loads. Wear loss of the composites were found to decrease with increasing hardness which increased with increasing TiB2 particle volume fraction. However, increasing the applied load and sliding distance increased the wear loss. Wear surface examinations showed that various wear mechanisms were effective in wear of the composites.

Comparative Study of Al/TiB2 Composites Manufactured by Underwater and Direct Shock Wave Consolidation

2011 ◽  
Vol 673 ◽  
pp. 231-236 ◽  
Author(s):  
H. Eskandari ◽  
H.M. Ghasemi ◽  
M. Emamy ◽  
Kazuyuki Hokamoto
Keyword(s):  
Shock Wave ◽  
Bending Strength ◽  
Volume Fraction ◽  
Direct Method ◽  
Particle Volume Fraction ◽  
Aluminum Matrix ◽  
Tib2 Particle ◽  
Aluminum Matrix Composites ◽  
Particle Volume ◽  
Tib2 Particles

Aluminum matrix composites containing of 10, 20 and 30 vol% TiB2 particles were compacted by underwater and direct shock wave consolidation methods. SEM and Optical Microscopic examination, hardness and bending strength measurements were used to characterize the samples. It is observed that there were different distributions of TiB2 particles in recovered compacts by each method. In the direct method, the distribution of TiB2 particles at the center and at the periphery of the sample was different whereas in the underwater method there was a uniform microstructure in the sample. The microhardness of the compacts increased with increasing TiB2 particle volume fraction in both methods. The results showed highest bending strength for the composite containing 20 vol% TiB2 particles.

scholarly journals Cold Forming of Al-TiB2 Composites Fabricated by SPS: A Computational Experimental Study

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3456 ◽  
Author(s):  
Elad Priel ◽  
Nissim U. Navi ◽  
Brigit Mittelman ◽  
Nir Trabelsi ◽  
Moshe Levi ◽  
...  
Keyword(s):  
Yield Stress ◽  
Damage Mechanics ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Continuum Damage Mechanics ◽  
Tib2 Particle ◽  
Particle Volume ◽  
Cold Forming ◽  
Effective Yield

The mechanical response and failure of Al-TiB2 composites fabricated by Spark Plasma Sintering (SPS) were investigated. The effective flow stress at room temperature for different TiB2 particle volume fractions between 0% and 15% was determined using compression experiments on cylindrical specimens in conjunction with an iterative computational methodology. A different set of experiments on tapered specimens was used to validate the effective flow curves by comparing experimental force–displacement curves and deformation patterns to the ones obtained from the computations. Using a continuum damage mechanics approach, the experiments were also used to construct effective failure curves for each material composition. It was demonstrated that the fracture modes observed in the different experiments could be reproduced in the computations. The results show that increasing the TiB2 particle volume fraction to 10% results in an increase in material effective yield stress and a decrease in hardening. For a particle volume fraction of 15%, the effective yield stress decreases with no significant influence on the hardening slope. The ductility (workability) of the composite decreases with increasing particle volume fraction.

Effect of the Rotating Speed of Centrifugal Machine on Microstructures and Properties of Recycled WCP/Fe-C Composites

2011 ◽  
Vol 704-705 ◽  
pp. 1000-1005
Author(s):  
Yan Pei Song ◽  
Yong Kai Li ◽  
Hui Gai Wang
Keyword(s):  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Wear Behaviour ◽  
Particle Volume ◽  
Rotating Speed ◽  
Centrifugal Machine ◽  
The Dead ◽  
Recycled Composites ◽  
The Impact

The dead or scrap WCP/Fe-C composites parts were remelted via medium frequency induction furnace. Two recycled composites rings were made of the remelted mixture by centrifugal casting method at 720rpm and 920rpm, respectively. The effect of rotating speed of centrifugal machine on microstructures and properties of the recycled composites rings were investigated by mechanical property tester, SEM, EDS, and XRD. The results show that the recycled rings are a composite structure consisting of outer recycled composites region reinforced with undissoved WCP and core Fe-C alloy region unreinforced. The undissoved WCP-distribution in the recycled composites region is even. At the rotating speed of 720 rpm, the particle volume fraction in the recycled composites region reaches 54 vol.%, the hardness and impact toughness attain to HRC55.8 and 3.5J/cm2, respectively. As the rotating speed is raised to 920 rpm, the particle volume fraction rises to about 70 vol.%, the hardness increases to HRC63.3 and yet the impact reduces to 2.8 J/cm2. The microstructure in the inner Fe-C alloy region consists of bainitic, precipitated carbides with short rod like shape and graphite phase. Finally, the high-speed sliding wear behaviour of the recycled composites rings was investigated in the paper. Keywords: The dead or scrap composites parts; Recycled composites; rotating speed of centrifugal machine; Microstructures and properties.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

A simulation and experimental study on particle volume fraction of PMMA suspension in centrifugal fields

2021 ◽  
Author(s):  
Yosephus Ardean Kurnianto Prayitno ◽  
Tong Zhao ◽  
Yoshiyuki Iso ◽  
Masahiro Takei
Keyword(s):  
Experimental Study ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume

Solidification Processing of Functionally Graded Materials by Sedimentation

1999 ◽  
Author(s):  
J. W. Gao ◽  
S. J. White ◽  
C. Y. Wang
Keyword(s):  
Functionally Graded Materials ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Computer Code ◽  
Functionally Graded ◽  
Particle Volume ◽  
Particle Sedimentation ◽  
Graded Materials ◽  
Free Zone ◽  
Free Region

Abstract A combined experimental and numerical investigation of the solidification process during gravity casting of functionally graded materials (FGMs) is conducted. Focus is placed on the interplay between the freezing front propagation and particle sedimentation. Experiments were performed in a rectangular ingot using pure substances as the matrix and glass beads as the particle phase. The time evolutions of local particle volume fractions were measured by bifurcated fiber optical probes working in the reflection mode. The effects of various processing parameters were explored. It is found that there exists a particle-free zone in the top portion of the solidified ingot, followed by a graded particle distribution region towards the bottom. Higher superheat results in slower solidification and hence a thicker particle-free zone and a higher particle concentration near the bottom. The higher initial particle volume fraction leads to a thinner particle-free region. Lower cooling temperatures suppress particle settling. A one-dimensional solidification model was also developed, and the model equations were solved numerically using a fixed-grid, finite-volume method. The model was then validated against the experimental results, and the validated computer code was used as a tool for efficient computational prototyping of an Al/SiC FGM.

Shock-Induced Multiphase Instability in a High Volume Fraction Finite-Thickness Particle Layer

2021 ◽  
Author(s):  
Bertrand Rollin ◽  
Frederick Ouellet ◽  
Bradford Durant ◽  
Rahul Babu Koneru ◽  
S. Balachandar
Keyword(s):  
Shock Tube ◽  
Volume Fraction ◽  
Solid Phase ◽  
Particle Volume Fraction ◽  
Finite Thickness ◽  
Spherical Particles ◽  
Shock Strength ◽  
Particle Volume ◽  
Particle Cloud ◽  
Particle Layer

Abstract We study the interaction of a planar air shock with a perturbed, monodispersed, particle curtain using point-particle simulations. In this Eulerian-Lagrangian approach, equations of motion are solved to track the position, momentum, and energy of the computational particles while the carrier fluid flow is computed in the Eulerian frame of reference. In contrast with many Shock-Driven Multiphase Instability (SDMI) studies, we investigate a configuration with an initially high particle volume fraction, which produces a strongly two-way coupled flow in the early moments following the shock-solid phase interaction. In the present study, the curtain is about 4 mm in thickness and has a peak volume fraction of about 26%. It is composed of spherical particles of d = 115μm in diameter and a density of 2500 kg.m−3, thus replicating glass particles commonly used in multiphase shock tube experiments or multiphase explosive experiments. We characterize both the evolution of the perturbed particle curtain and the gas initially trapped inside the particle curtain in our planar three-dimensional numerical shock tube. Control parameters such as the shock strength, the particle curtain perturbation wavelength and particle volume fraction peak-to-trough amplitude are varied to quantify their influence on the evolution of the particle cloud and the initially trapped gas. We also analyze the vortical motion in the flow field. Our results indicate that the shock strength is the primary contributor to the cloud particle width. Also, a classic Richtmyer-Meshkov instability mixes the gas initially trapped in the particle curtain and the surrounding gas. Finally, we observe that the particle cloud contribute to the formation of longitudinal vortices in the downstream flow.

Alignment of Nanoplates in Lamellar Diblock Copolymer Domains and the Effect of Particle Volume Fraction on Phase Behavior

2018 ◽  
Vol 7 (12) ◽  
pp. 1400-1407 ◽  
Author(s):  
Nadia M. Krook ◽  
Jamie Ford ◽  
Manuel Maréchal ◽  
Patrice Rannou ◽  
Jeffrey S. Meth ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Diblock Copolymer ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume
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