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As the title of the project suggests, it is a research on the effect of cutting force in milling of aluminium hybrid metal matrix composites. The combination of composites are Aluminium 6061-Alumina-Graphite.Face milling is performed on the fabricated workpiece. The composite is fabricated using stir casting technique.The experiments are designed according to the L27 model in taguchi method. The reults indicated that variation of alumina content in the workpiece or specimens was the predominant factor, feed rate was the second most predominant factor. Speed had less effect on measuring the cutting forces. This combination of composites is mainly used in the manufacturing of cylinder liners in automobiles. The reason is the presence of alumina which increases the hardness of the workpiece. Graphite is added due to its lubricating properties. Al6061 is chosen for its good machinable properties. This topic has immense research possibilities that can change the face of manufacturing industry.
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Experimental Investigation on Cutting Force in Milling of Al Hybrid Metal Matrix Composites
Adithya Krishnakant. C
Objective To develop aluminium based alumina and graphite particulate hybrid MMCs with an objective to develop a conventional low cost method of producing MMCs .
Machining of composite materials is difficult to carry out due to the anisotropic structure of the composite and to the high abrasiveness of their reinforcing constituents. Graphite added to the composite acts as self lubricant and enhances the machinability. Face milling is performed with using tungsten carbide insert to study the cutting force characteristics.
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
Al(6061) Al2O3Graphite
Stir casting
spSpecimen 1 Specimen 2 Specimen 3
Milling Operation
Weight%
Process Flow
90:5:5 85:10:5 80:15:5
: :http://www.google.co.in/search?tbm=isch&hl=en&source=hp&biw=1366&bih=667&q=stir+casting&gbv=2&oq=stir+casting&aq=f&aqi=g1&aql=&gs_sm=e&gs_upl=2590l10952l0l11429l12l12l0l3l3l0l614l1785l3-2.1.1l4l0
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Cutting force
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
Fabrication of composites
Furnace setup Furnace operation Figure showing stirrer
Stir casting
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
Experimental procedure
Preheated alumina (500o C for 2hours)
Preheated graphite (250o C for 1hour)
Melting of Al-6061 at 730o C
Stirring process of Al/Al203/Graphite
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
Pouring of molten metal into die
Hardness test values
The fabricated composite is tested in Rockwell hardness tester. The result obtained are as follows for a applied load of 100kg and a 1/16” ball indentor and B scale is used.
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
Plan of Experiments
There are three parameters in the design of experiment were considered. They are speed, feed and weight fraction of alumina. Taguchi techniques have been widely used in engineering analysis. The techniques of Taguchi consists of plan of experiment with the objective of acquiring data in a controlled way, executing this experiments and analyzing data in order to obtain information about the behavior of a given process. Conducting Taguchi experiments in terms of orthogonal array allows the effect of several parameters to be determined efficiently and is an important technique in robust design. The total no. of experiments may be extremely large when many no. of cutting parameters are considered. Orthogonal array is the good method to reduce the no. of experiments. In this study L27 orthogonal array is used.
Exp no.Speed
(rpm)
feed rate
(mm/min) % alumina
1 1500 50 5
2 1500 50 10
3 1500 50 15
4 1500 100 5
5 1500 100 10
6 1500 100 15
7 1500 150 5
8 1500 150 10
9 1500 150 15
10 3000 50 5
11 3000 50 10
12 3000 50 15
13 3000 100 5
14 3000 100 10
15 3000 100 15
16 3000 150 5
17 3000 150 10
18 3000 150 15
19 4500 50 5
20 4500 50 10
21 4500 50 15
22 4500 100 5
23 4500 100 10
24 4500 100 15
25 4500 150 5
26 4500 150 10
27 4500 150 15
Plan of Experiments
Variable levels used in the experimental plan
Variable/ Code Symbol Levels
1 2 3
Spindle speed (rpm) N 1500 3000 4500
Feed rate(mm/min) F 50 100 150
Alumina(%) 5 10 15
Force Measurement- Dynamometer
1. Transducing stage – Conversion into another suitable variable.
2. Conditioning stage- Amplification , Filtration and Stabilization.
3. Read-out stage- Reading or Recording
General Measurement Procedure:
Transducing stage Conditioning stage Read-out stage
Experiment Procedure
Face milling is conducted on ARIX VMC 100 CNC Vertical machining centre. The Machining samples were prepared in the form of 190×170×10 mm. The tungsten carbide insert( 2 no.) cutter of 16mm diameter is employed. Coolant was not in all of the milling tests. A three-component (Model: KISTLER 9257B) dynamometer platform was used to measure cutting force.
CNC Vertical machining center
Experimental setup for cutting force measurement
Cutting Action
Machined Surfaces
Cutting Force Measurement Results from software
1. For speed =1500 rpm, feed rate =50 mm/min and 5% Alumina
2. For speed =1500 rpm , feed =100 mm/min and 10% alumina
3. For speed =1500 , Feed =150 mm/min and 15% alumina
4. For Speed =1500 rpm, Feed =50 mm/min and 15% alumina
5. For speed =1500 rpm , feed =150 mm/min and 10% alumina
Results and Discussions:
Variation of Cutting Force vs Feed rate and Speed for different weight fractions of alumina
Conclusions:
[1] The feed rate and weight fraction of alumina are the predominant factors followed by cutting speed. The results reveal that as the feed rate increases from 50,100 and 150 mm/min, the cutting force increases for all the spindle speeds for all the work piece materials. When feed rate is increased from 50 to 150 min/min, the value of cutting force (from 55.42 to 133.91 N) increases by almost 58.61% (by addition of 5% alumina and cutting speed is 1,500 rpm) [2] when weight fraction of alumina increases from 5 to 15 % the value cutting forces increases from 55.42N to 133.91N by almost 58.61%.
[3] when spindle speed is increased from 1,500 to 4,500 rpm the value of cutting force (from 55.42N to 99.32N) increases by almost 44.2% (by addition of 5% alumina and feed rate is 50 mm/min).
Future scope:
The present study can be further extended to evaluate the machinability by assessing surface roughness and tool wear and Fracture toughness for the same material.
Experimental Investigation on cutting force of Milling of Al Hybrid MMC
References:
1. M.K. Surappa (2003). Aluminium matrix composites: Challenges and Opportunities, vol. 28 part 1&2 Sadhana.
2. Zhengang Liu, Guoyin Zu, Hongjie Luo, Yihan Liu and Guangchun Yao (2010). Influence of Mg Addition on Graphite Particle Distribution in the AL Alloy Matrix Composites, vol. 26(3). J. Mater. Sci. Technology 244-250.
3. Luo Xiaowei, Robin Jean-Charles and YU Suyuan (2003). Effect of Temperature on Graphite Oxidation Behaviour, J. nucengdes.11.004
4.K. Palanikumar (2206)Application of Taguchi and response surface methodologies for surface roughness in machining glass fiber reinforced plastics by PCD tooling, , Springer-Verlag London Limited 2006.5.Rajesh Kumar Bhushan, Sudhir Kumar, S.Das(2009). Effect of machining parameters on surface roughness and tool wear for 7075 Al alloy SiC composite, Springer-Verlag London Limited .
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