The Effect of Suspension Casting on the Properties of Fly-Ash Particle Reinforced Al Matrix Composites

2012 ◽  
Vol 581-582 ◽  
pp. 794-797 ◽  
Author(s):  
Zheng Wu Jiang ◽  
Hong Feng Luo ◽  
Zhu Jun Li

The effect of suspension casting on the properties of fly-ash particle reinforced aluminum matrix composites is studied in this paper. The result shows that adding suspending agent with the same composition of aluminum matrix ,can improve the microstructure of aluminum matrix composites contain 5vol% fly-ash particle when addition temperature is 800°Cand addition quantity of suspending agent is 3%. The hardness and wear-resistance of fly-ash particle reinforced aluminum matrix composites can be increased by 13.10% and 20.10%.

2013 ◽  
Vol 856 ◽  
pp. 142-146
Author(s):  
Qiong Wu ◽  
Da Peng Li ◽  
Xiao Ju Shui

When SiC particles are added into aluminum, property of aluminum is greatly improved during a reinforcing phase to produce particle reinforced aluminum composites. However, cutting tools wear out quickly and it is difficult to meet machining accuracy and surface quality requirements due to the rough surface produced by the reinforcement process. This paper presents a simulation model of SiC particle-reinforced aluminum matrix composites is established considering particles, cohesive elements, and material matrix. Stress distribution and surface roughness are analyzed for SiC/Al matrix composites based on the cutting process. Experiments are performed to test the degree of surface roughness using different cutting parameters. The relationship of cutting depth, cutting velocity, and feed rate per tooth to surface roughness degree is obtained for SiC/Al matrix composites. The optimization of cutting process is performed based on simulation. The results lay a foundation on the optimization of machining processes for metal matrix composites.


2020 ◽  
Vol 29 ◽  
pp. 2633366X2097749
Author(s):  
Wei Yan ◽  
Mingchen Ma ◽  
Heyi Kang ◽  
Qian Li ◽  
Hongqun Tang ◽  
...  

Nanodiamonds (NDs) have the characteristics of both diamonds and nanomaterials. However, it is difficult to disperse NDs, and this is why there is less research regarding NDs in the field of aluminum matrix composites. In the present work, NDs were modified via surface oxidation, and ND/Al matrix composites were successfully prepared via mechanical ball milling and vacuum sintering. The effects of different volume fraction of NDs (1%, 3%, 5%, 7%) after surface oxidation on the ND/Al matrix composite were analyzed using a metallographic microscope, scanning electron microscope, infrared spectrometer, X-ray diffractometer, microhardness tester, and universal testing machine. The results show that the optimal temperature of surface oxidation treatment is 673 K, which effectively purifies the surface of ND and introduces appropriate C=O functional groups. NDs are uniformly distributed in the aluminum matrix, and no harmful Al4C3 phase is formed. With an increase in the volume fraction of NDs, the grain size of the matrix first decreases and then increases, and the ultimate compressive strength first increases and then decreases. The volume fraction of ND with better comprehensive performance is 3% and the yield strength increased by 19%.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1284 ◽  
Author(s):  
Feng Qiu ◽  
Hao-Tian Tong ◽  
Yu-Yang Gao ◽  
Qian Zou ◽  
Bai-Xin Dong ◽  
...  

Bimodal hybrid in-situ nano-/micro-size TiC/Al composites were prepared with combustion synthesis of Al-Ti-C system and hot press consolidation. Attempt was made to obtain in-situ bimodal-size TiC particle reinforced dense Al matrix composites by using different carbon sources in the reaction process of hot pressing forming. Microstructure showed that the obtained composites exhibited reasonable bimodal-sized TiC distribution in the matrix and low porosity. With the increasing of the carbon nano tube (CNT) content from 0 to 100 wt. %, the average size of the TiC particles decreases and the compressive strength of the composite increase; while the fracture strain increases first and then decreases. The compressive properties of the bimodal-sized TiC/Al composites, especially the bimodal-sized composite synthesized by Al-Ti-C with 50 wt. % CNTs as carbon source, were improved compared with the composites reinforced with single sized TiC. The strengthening mechanism of the in-situ bimodal-sized particle reinforced aluminum matrix composites was revealed.


Author(s):  
Weiping Xu ◽  
Liming Ke ◽  
Li Xing ◽  
Zhifeng Zhang ◽  
Xia Zhao

Carbon nanotubes (CNTs) reinforced Al matrix composites were prepared by friction stir processing (FSP). The effect of CNTs content on the wearing performance and hardness of Al matrix composites was studied. Results show that CNTs reinforced Al matrix composites by FSP are to create a good dispersion of the CNTs in the matrix and to achieve a good combination with the matrix. The interface of CNTs and pure aluminum matrix is smooth, no defects and is one kind of mechanical bonding interface. There are a large number of dislocations. CNTs can strengthen the matrix composites effectively and obviously improve the hardness of the composites. With increasing CNTs content, CNTs can also improve the wear performance of the matrix composites.


2021 ◽  
Vol 16 (3) ◽  
pp. 112-123
Author(s):  
Mahmut Can Şenel ◽  
Mevlüt Gürbüz

In the current work, nano boron nitride (BN) reinforced aluminum (Al) matrix composites with different BN amounts (0.5-2wt.%) were produced by the powder metallurgy(PM) route. This fabrication method consists of dispersing, filtering, mixing, drying, compaction, and sintering processes. The density, compressive strength, micro Vickers hardness, microstructure, and phase structures of Al-BN composites and pure Al were examined. The obtained results indicated that minimum porosity (3.2%), highest density (~2.61g/cm3), Vickers hardness (~50HV), and compressive strength (~168MPa) were obtained at 1%BN reinforced aluminum matrix composite. A tremendous enhancement in Vickers hardness and compressive strength of %1BN reinforced Al matrix composite was achieved as ~61% and ~110% compared to pure Al. Consequently, the mechanical strength of BN reinforced Al-based composites enhanced up to 1% nano boron nitride amount. Due to the clumping of BN nanoparticles, the mechanical strength decreased after this content.


2011 ◽  
Vol 46 (13) ◽  
pp. 1521-1534 ◽  
Author(s):  
H Kaftelen ◽  
ML Öveçoğlu

Elemental aluminum (Al) powders reinforced with 1–10 wt% of ultra-dispersed nanodiamond (UDD) powders were ball-milled in a SpexTM Mixer/Mill between 0 and 120 min followed by consolidation and sintering. X-ray diffraction analyses on the ball-milled powders revealed only α-Al peaks, whereas Al4C3 phase was identified along with α-Al in all sintered composites. Increasing the addition of nanodiamond to Al-matrix resulted in improved hardness of both ball-milled and sintered composites. The wear resistances of the Al-UDD composites were significantly improved with increasing UDD contents. Under similar load and sliding conditions, the wear resistance of Al matrix composite containing 10 wt% nanodiamond enhances about 40 times when compared with unreinforced aluminum.


2008 ◽  
Vol 395 ◽  
pp. 157-178
Author(s):  
Ji Xiong Han ◽  
Yong Ching Chen ◽  
Vijay K. Vasudevan

Studies were carried out on microstructure evolution and mechanical behavior of an Al matrix–nanoscale Al2O3 particulate-reinforced composite. The thermal stability of the composite, evaluated by heat treating specimens at temperatures from 300 to 600 °C for times varying from 1 to 100 hours, revealed that the nano-sized (30-100 nm) Al2O3 particles present in the as-received/ascast material coalesced into larger particles, but with sizes still in the 100 to 500 nm range. Despite the coarsening of the particles, high hardness was retained. The tensile properties of both the as-cast DSC material and those thermally soaked for 500 hours at a number of temperatures were evaluated. The results showed that the yield strength was quite high (283 MPa) at room temperature and decreased nearly linearly with temperature, though values as high as 110 MPa were obtained at 400oC. Thermal soaking did not have a detrimental effect on strength. Although the macroscopic ductility of both unsoaked and soaked materials remained quite low over the entire temperature range, SEM observations of the fracture surfaces provided substantial evidence for high localized plasticity as manifested by stretching, tearing and void formation in the Al matrix around the oxide particles. Possible strengthening mechanisms, including grain size reduction, Orowan bypass and forest hardening, were considered and modeled. Good agreement between the calculated and experimental strengths was obtained, and majority of the strengthening at room temperature was found to come from forest hardening (i.e, increase in dislocation density caused by the thermal expansion mismatch between Al and Al2O3), with secondary contributions from the Orowan mechanism. TEM observations provided confirmatory evidence for these mechanisms. The decrease in strength at higher temperatures was attributed to a diminishing contribution from forest hardening due to recovery processes.


2013 ◽  
Vol 457-458 ◽  
pp. 131-134 ◽  
Author(s):  
Tao Fan ◽  
Cong Li Xiao ◽  
Yan Rong Sun ◽  
Hong Bo Li

The aim of this study is to investigate the effect of SiC particle pretreatment, aluminum matrix particle size and sintering temperature on relative density, hardness, microstructure and wear resistance to SiC particle einforced aluminum matrix composites. To this end, the amount of 16.7 wt.% SiC with average particle sizes 20μm was used along with pure aluminum of average particle size of 75 μm and 25μm. Powder metallurgy is a method used in the fabrication of this composite in which the powders were mixed using a planetary ball mill. By analyzing SEM micrograph and the Property test, it is concluded that SiC particle pretreatment has significant effect on the morphology of pecimens. pretreatment increase the interface adhesion, improve the wettability. SiC is uniformly distributed in the matrix, with good relation to the substrate, the maximum hardness is 51.1HB, the minimum wear rate is 0.1684%, while the density is 97.3%.For the same SiC content and particle size, the smaller the particle size of aluminum matrix is, the higher wear resistance of composite materials is on condition that others are same, the higher sintering temperature and the higher the wearability of composites, the wear resistance of the composite material is significantly improved after SiC pre-processing.The relative density increases with increasing aluminum matrix particle sizes under the same pressure and the holding time. The actual density of all samples reached the theoretical density over 96%, to a maximum of 98.9%.


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ridvan Gecu ◽  
Ahmet Karaaslan

This study aims to investigate the effect of volume fraction of commercially pure titanium (CP-Ti) on microstructural, mechanical, and tribological features of A356 aluminum matrix composites. Vacuum-assisted melt infiltration casting was performed to produce composites with 50%, 65%, 75%, and 80% CP-Ti contents. CP-Ti sawdusts were assembled under mechanical pressure in order to attain porous one-piece CP-Ti preforms which were infiltrated by A356 melt at 730 °C under 10−5 Pa vacuum atmosphere. TiAl3 layer was formed at the interface between A356 and CP-Ti phases. Owing to increased diffusion time through decreased diffusion path length, both thickness and hardness of TiAl3 phase were increased with increasing CP-Ti ratio, whereas the best wear resistance was obtained at 65% CP-Ti ratio. The main reason for decrease in wear resistance of 75% and 80% CP-Ti reinforced composites was fragmentation of TiAl3 layer during wear process due to its excessively increased brittleness. Strongly bonded TiAl3 phase at the interface provided better wear resistance, while weakly bonded ones caused to multiply wear rate.


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