Fabrication of Al-Based Composites Cylinder Reinforced with In Situ Si/Mg2Si Particles and the Research of its Bench Test

2017 ◽  
Vol 909 ◽  
pp. 116-121
Author(s):  
Xue Dong Lin ◽  
Chang Ming Liu ◽  
Jian Bo Lu
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Maximum Output Power ◽  
Internal Surface ◽  
Bench Test ◽  
Maximum Output ◽  
Particle Volume

The centrifugal casting process was adopted to fabricate Al-30Si-8Mg composites tubes reinforced with in-situ particles, which was used to produce the cylinders used in 149cc engine by high pressure die casting. The relations between the microstructures along the radial direction and the hardness and wear resistance of the casting were researched. The internal surface of the cylinder was treated and a bench test for the engine was carried out. The results show that, 1) a large number of primary Si/Mg2Si particles are segregated and enriched in the inner layer of the Al-30Si-8Mg casting, while no particle is in the outer layer, and the maximum particle volume fraction is up to 31.9 vol. %; 2) the region which has more primary particles, the hardness value is higher, and the wear resistance is better as well in the casting; 3) the cylinder assembled on the air-cooled engine successfully passes through the endurance test for 200 hours, and the maximum output power and torque reach 8.18 KW and 10.77 N·m, respectively, while a slight scuffing occurs on the internal surface of the cylinder in the later phase of the test.

Analysis on the Distribution Law of WC Particles during Centrifugal Casting Process

2011 ◽  
Vol 117-119 ◽  
pp. 1610-1613
Author(s):  
Zhen Kai Zhao ◽  
Yan Pei Song ◽  
Zhi Ming Feng
Keyword(s):  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Composite Layer ◽  
Theoretical Data ◽  
Casting Process ◽  
Mathematical Equation ◽  
Distribution Law ◽  
Particle Volume ◽  
Gradient Distribution

The mathematical physical model of the unmelted WC particle distribution in the centrifugal force field was established in cylindrical coordinate system using continuity theory and hydromechanics. According to the migration rule of WC particle in the Fe-C alloy melt under centrifugal field, the mathematical equation of particle volume fraction distribution including centrifugal casting parameters was formulated. The mathematical equations were calculated by solving the mathematical equation with numerical analysis, and also the distribution regularity of WC particle in composite layer under different temperature and different Centrifugal speed was achieved. The results show that the particle reinforced composite with a gradient distribution along thickness was prepared by centrifugal casting. The gradient distribution of the particle changes with pouring temperature and centrifugal speed. And the theoretical data accord with experiment data compared to the experimental measurement.

Simulations on the gelling process of particle suspension systems for in-situ preparing porous materials in a capillary

2015 ◽  
Vol 29 (04) ◽  
pp. 1550015 ◽  
Author(s):  
J. Wang ◽  
J. J. Xu ◽  
Y. Yang ◽  
X. J. Wang ◽  
X. Luo ◽  
...  
Keyword(s):  
Density Distribution ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Capillary Wall ◽  
Particle Suspension ◽  
Aggregation Kinetics ◽  
Particle Volume ◽  
Capillary Size ◽  
Gelling Process

The gelling process of particle suspension in a capillary which is crucial for in-situ preparing small size foam products has been simulated with an off-lattice diffusion limited cluster aggregation (DLCA) model by the three-dimensional Monte Carlo simulations. The effects of the model parameters, such as the interaction between capillary wall and particles, particle volume fraction, capillary size etc. on the density distribution of the system have been fully explored. And the aggregation kinetics process over a broad range of volume fractions and interactions have also been discussed. The results show that the geometric constraint of capillary can be analogous to a weak repulsive interaction between capillary wall and particles. And we found that as the capillary size or particle volume fraction increase, particle concentration distribution will be more uniform with other parameters constant. Porous network with relatively uniform density distribution can be also obtained through controlling the interaction between capillary wall and particles. In addition, by analyzing the aggregation kinetics process, we found that the attraction of capillary wall dramatically reduces the probability of gelation in the small-scale capillary. The obtained results will be of great importance in controlling the density distribution of porous materials prepared by in-situ methods.

Fabrication of Al-Si-Mg Functional Composites Engine Cylinder and its Bench Test

2018 ◽  
Vol 759 ◽  
pp. 15-19 ◽  
Author(s):  
Xue Dong Lin ◽  
Chang Ming Liu ◽  
Jian Sun
Keyword(s):  
Aluminum Alloy ◽  
Die Casting ◽  
Centrifugal Casting ◽  
Liquid Aluminum ◽  
Maximum Output Power ◽  
Cylinder Liner ◽  
Bench Test ◽  
Maximum Output ◽  
Functional Composites ◽  
Engine Cylinder

The centrifugal casting method was adopted to fabricate Al-25Si-8Mg functional composites tubes reinforced with in-situ particles to acquire the Al-Si-Mg composites cylinder liner which was used to produce 600 cc aluminum alloy engine cylinder for the first time through the low pressure die casting. The inner layer of the cylinder was corroded and a bench test was carried out to test the performance of the engine assembled with the cylinder. It is found that a large number of primary Si/Mg2Si particles are segregated in the inner layer of Al-25Si-8Mg tubes in the centrifugal filed, forming the particle reinforcement layer. During die-casting process, the cylinder bore needs to be filled with refractory cotton to avoid the running-out of liquid aluminum alloy. Using the Al-Si-Mg composites cylinder, the measured maximum output power and output torque of the 600 cc water-cooled engine reach 22.66 KW and 44.37 N·m, respectively. Temperature monitoring shows a reduction of 5~8 degrees than usual.

scholarly journals Microstructure Characterization of Aluminium Syntactic Functionally Graded Composites Containing Hollow Ceramic Microspheres Manufactured by Radial Centrifugal Casting

2008 ◽  
Vol 587-588 ◽  
pp. 207-211 ◽  
Author(s):  
S.C. Ferreira ◽  
Alexandre Velhinho ◽  
L.A. Rocha ◽  
Francisco Manuel Braz Fernandes
Keyword(s):  
Metal Matrix ◽  
Radial Direction ◽  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Particle Diameter ◽  
Functionally Graded ◽  
Particle Volume ◽  
Centrifugally Cast ◽  
Functionally Graded Composites

Syntactic functionally graded metal matrix composites (SFGMMC) are a class of metallic foams in which closed porosity results from the presence of hollow ceramic microspheres (microballoons), whose spatial distribution varies continuously between the inner and the outer section of the part, thus resulting in a continuous variation in properties. In this work, aluminiumbased SFGMMC rings were fabricated by radial centrifugal casting. The graded composition along the radial direction is controlled mainly by the difference in the centrifugal forces which act on the molten metal matrix and the ceramic particles, due to their dissimilar densities. In this case where the density of the SiO2-Al2O3 microballoons is lower than that of molten aluminium, the particles show a tendency to remain closer to the inner periphery of the ring. Thus the microballoon volume fraction increases along the radial direction of the ring from the outer to the inner periphery; in other words, the particle-rich zone is limited to an inner layer of the ring. Precursor conventional MMCs were prepared by stir-casting from the constituent materials, by homogeneously dispersing commercial SiO2-Al2O3 microballoons (particle size: 50 µm; particle volume fraction: 5 and 10 %) within a molten commercial Al-7Si-0.3Mg (A356) alloy. The resulting MMCs were then re-melt and centrifugally cast in order to produce the functionally graded composites. Particle gradients in the centrifugally cast composites were investigated by quantitative image analysis of optical micrographs (for the estimation of the particle volume fraction, mean particle diameter and porosity 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.

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