Study the Effect of Wetting between Fly Ash – Aluminum Alloy on Wear Resistance of Composites...
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Transcript of Study the Effect of Wetting between Fly Ash – Aluminum Alloy on Wear Resistance of Composites...
Study the Effect of Wetting between Fly Ash – Aluminum Alloy on Wear Resistance of Composites
Presenter : Liang Ging. Fan
Author : Shueiwan H. Juang, Liang Ging. Fan, Shao Jun. Gu
112/04/10
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Fly Ash
Properties Class F Class C
(SiO2)+(Al2O3)+(Fe2O3), min, % 70.0 50.0
(SO3), max, % 5.0 5.0
Moisture Content, max, % 3.0 3.0
Loss on ignition, max, % 6.0 6.0
ASTM C618 、 CNS 3036
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Chemical Reactions
3232
322
OAlFe2O2FeAl2
OAlSi2
3SiO
2
32Al
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Aluminum—Fly Ash, ALFA
Al Cu Fe Mg Mn Ni Si Sn Zn
other 1.5-3.5 <1.30 <0.30 0.50 9.6~12.0 9.6~12.0 <0.20 <1.00
SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O SO3
52.73 26.87 5.11 - - - - 0.39
Chemical composition of fly ash ( wt% )
Chemical composition of ADC12 Al alloy ( wt% )
• JIS designation, ADC12, was selected as the base metal.
• Fly ash was gotten from Mailiao power plant (Taiwan) and its density is ranged about 2.0~2.5 (g/cm3).
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SEM — Micrographs of Fly ash
(a) (b)
SEM micrograph showing (a) a complete particle of fly ash and (b) rough surface appeared on some particles.
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Wetting
solid
liquid
lyslsvSC
SC : Spreading Coefficient γ : Interfacial Energy Θ : contact angle Al matrix
porosity
fly ash
SEM micrograph of ALFA composite.
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Experimental Procedure
Pre-treatment of fly ash
Mixing with stirring
Gravity casting
Property Measurement of composite castings
Wetting evaluation
yes
no
Start
End
Matrix metal
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Influence Factors of Fly Ash on Process
• Particle characteristics Density, size, shape and volume fraction
• Etch cleaning Remove the adsorbed contaminants
• Pre-heated Degas, de-moisture
clean fly ash.
untreated
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Optical Micrographs of False ALFA
Si
Al-Si
fly ash clusterAl matrix
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Experiment Design • Matrix: Aluminum alloys, ADC 12
• Addition: 3wt% Mg into the liquid metal to reduce the surface tension.
• Fly ash being pickled by sulfuric acid and pre-heated at 700 ℃ for a specified period, added into the aluminum melt at 850 ℃ with different weight percentage, such as 0wt%, 2wt%, 4wt%, 6wt%, 8wt% and 10wt%, and followed by mechanical stirring with 500 rpm to obtain a well-mixed melt.
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Optical Micrographs of Accepted ALFA
Micrograph of ALFA composites formed by gravity casting: (a) a complete particle and (b) uniform distribution of fly ash particles.
(a) (b)
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Density Measurements ADC12 : 2.68 g/cm3
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Wear Tests• Wear behavior of ALFA composites tested using Pin-On-Disc
apparatus under a load of 9.8N and 18.6N at a constant sliding velocity of 0.5 m/s and sliding distance is 50 m.
• Counterpart material used in the wear tests was Cr steel ball with ¼ in. in diameter and HRC 58 in hardness.
abrasion tester
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Wear Tests
Load : 9.8 N Load : 18.6 N
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Conclusions• The test results revealed that the density of composites was decreased with
increasing fly ash percentage.
• Wear resistance of composites was improved as increasing fly ash percentage.
• Pretreatment of fly ash is the key to obtain a successful ALFA composite.
• In future, the die casting process will be introduced by virtue of runner passive stirring (RPS) to obtain a uniform distribution of fly ash inside metal matrix and a better structure by casting pressure.
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Thanks !!