Investigations for Mechanical Properties of Metal Matrix Composite Prepared by Combining FDM, Vacuum Moulding and Stir Casting

Transcription

1 th International & 6 th All India Manufacturing Technology, Design and Research Conference (AIMTDR ) December th th,, Investigations for Mechanical Properties of Metal Matrix Composite Prepared by Combining FDM, Vacuum Moulding and Stir Casting Rupinder Singh *, Sunpreet Singh, Sardar Singh * Production Engg. Dept., GNDEC, Ludhiana, 6, rupindersingh78@yahoo.com Production Engg. Dept., GNDEC, Ludhiana, 6, snprt.singh@gmail.com Production Engg. Dept., GNDEC, Ludhiana, 6, rupinderkhalsa@gmail.com Abstract There has been a critical need for development of aluminum (Al) based metal matrix composites (MMCs) for various rapid tooling (RT) applications. But hither to no work has been reported on investigations for mechanical properties of Al based MMC prepared by combining fused deposition modelling (FDM), vacuum moulding (VM) and stir casting (SC) process. In the present work an approach to macro-model the mechanical properties (like: surface roughness and dimensional accuracy) of Al based MMC prepared by combining FDM, VM and SC process have been proposed and applied. The relationship between output mechanical properties and other input parameters have been deduced by using Taguchi technique. For optimum surface roughness the best settings were at 7.% mixed in Al, of 7 AFS number and vacuum.n/mm and for dimensional accuracy it was % mixed in Al, of 7 AFS number and vacuum at. N/mm.. Introduction The development of Al based MMCs with tailor made properties (like: homogenous dispersion of ceramic material) and cost effective processing method is the need of the hour, Lee et al. (). Such type of MMCs developed have number of rapid tooling (RT) applications (like in dental and other biomedical needs, space craft etc.). The term composite broadly refers to a material system which is composed of a discrete constituent (the reinforcement) distributed in a continuous phase (the matrix) and which derives its distinguishing characteristics from the properties of its constituents, from the geometry and architecture of the constituents and from the properties of the boundaries (interfaces) between different constituents, Kathiresan and Sornar (). For developing MMC, SC process is one of the simplest and the most cost effective method of liquid state fabrication, Singla et al. (9), Singh et al. (), Singh et al. (). A dispersed phase (ceramic particles, short fibers) is mixed with a molten matrix metal by means of mechanical stirring. FDM is one of the rapid prototyping (RP) process which works on the principle of additive method, Sood et al. (9). In FDM process the part is fabricated by deposition of layers. This process is able to quickly fabricate complex-shaped, D parts directly from computer-aided design models. A plastic filament or metal wire is unwound from a coil and supplies material to an extrusion nozzle which can turn the flow on and off as shown in Figure. In VM the pattern made from wood is normally used, Kumar et al. (7). This process is different from sand casting as it does not required binder for sand holding. In this process polymer sheet is used to seal the open ends of mould, Kumar and Gaindhar (99). Figure Schematic of FDM(Sood et al.,9) The literature review reveals that lot of research work has been reported independently on development of MMC by SC, process, optimization of FDM and VM process. But hitherto very less work has been reported on combining of FDM, VM and SC -

2 Investigations for Mechanical Properties of Metal Matrix Composite Prepared by Combining FDM, Vacuum Moulding and Stir Casting for development of the MMC. So in the present work it is proposed to study mechanical properties like surface roughness (Ra) and dimensional accuracy( d) of MMC prepared by combining of FDM, VM and SC process.. Methodology Before going for the final experimentation, pilot experiments were conducted in order to analyze the contributing parameters and their levels. For the present study different sizes of ABS patterns were made on FDM. The input parameters of the pilot experiment were the vacuum conditions (which were with vacuum. N/mm and.6 N/mm, sand and 7, and s (Al- like molten %, Al-% ). The parameters metal temperature, plastic film thickness were kept constant for the components. The outpu parameter of the study was Ra and d of MMC. Table shows observations of pilot experimentation. The Ra was measured using surface roughness ester (Mitutoyo SJ-) and d was measured as difference in dimensions of the cast component from the nominal dimension (based upon actual drawing). Figure shows D view of the component.. The patterns diameters and thickness were taken mm and mm. Small size holes were made by the FDM in the pattern for the suction of vacuum to provide proper sticking of plastic film. No draft is required for pattern because the plastic film act as lubricant to strip the pattern from cavity. Figure D view of the pattern After conducting the pilot experimentation it has been observed that input parameters like vacuum, and have effect on the Ra as well as d of the MMC. For the optimization of process, design of final experiments was made according to Taguchi s L9 orthogonal array. Table shows control log for final experimentation. S. No. 6 S. No. Table Pilot experiment observations Compo sition Al-% Al-% Al-% Al-% Al-% Al-% Grain size (AFS No.) Vacuum (N/mm ) Table Control log for experimentation Composition Grain Size (AFS No.) Al-% Al-7.% 6 Al-% 7 Al-% Al-7.% 6 6 Al-% 7 7 Al-% 8 Al-7.% 6 9 Al-% 7. Result and Discussions Ra, µm d, mm Vacuum Pressure (N/mm ) Based upon Table, three repetitions of experiment were made as R, R and R for measurement of Ra and d (Ref. Table and ). Based upon Table and, Table, 6 shows sum of squares and signal to noise (S/N) ratio for present set of experiments. Based upon Table, Figure - shows the highest value of the S/N ratio and Ra w. r. t. to,, and vacuum respectively. Similarly, based upon Table 6, Figure 6 shows the highest value of the S/N ratio and d w. r. t. input parameters. -

3 th International & 6 th All India Manufacturing Technology, Design and Research Conference (AIMTDR ) December th th,, Table Observations of final experimentation for Ra (µm) Table 6 S/N ratio for d S. No. Sum square S/N ratio Average S. No R R R Table Observations of final experimentation for d (mm) S.No R R R % Composition of Figure S/N ratio and Ra w. r. t. to..... S. No Table S/N ratio for Ra Sum square S/N ratio Average Grain size AFS no Figure S/N ratio and Ra w. r. t. to

4 Investigations for Mechanical Properties of Metal Matrix Composite Prepared by Combining FDM, Vacuum Moulding and Stir Casting Vacuum Figure S/N ratio and Ra w. r. t. 7. of (%) Figure 6 S/N ratio and d w. r to vacuum.9.6. t. to 6 7 Figure 7 S/N ratio and d w. r. t. to.9.6. d dimensional accuracy value decreases with an increase in percentage from % to 7.%. This may be because of the fact that at parametric level i.e. 7.%, the distribution of the solute is more uniform when compared to parameter i.e. %.Further, when the level increased from 7.% to % of tends to increase the Ra value (as shown in Figure ) may be attributed due to higher solute concentration. From Figure, it has been found that with an increase in the AFS No. of sand grain size Ra of the casting decreases. It is well known that increase in ASF No. leads to finest sand. So, in present case minimum Ra of the casting produced at higher AFS No. of the sand. Further from Figure, it has been found that vacuum of. N/mm resulted into better suction and Ra of the castings too. However, with Lower value of vacuum (below. N/mmm ) there is non- the drag box uniform sealing of plastic film over resulted into torn surface of film. Similarly, Figures 6 shows that % with 7AFS and vacuum. N/mm resulted into better d. Figure 9 and Figure show the pie charts for percentage contribution of input parameters for Raand d. These results are valid at 9% confidence level. The confirmatory experiment was conducted which shows percentage improvement in Ra and d is.% and.6% respectively at proposed parametric settings. The results are in line with the observations made by other investigators, Gaindhar et al. (98), Singh and Singh (9), Singh (), Singh (), Singh et al. () vacume Figure 8 S/N ratio and d w. r. t dimensional accuracy to vacuum vacuum Error Figure 9 Contribution of various input parameters for Ra of MMC As observed from Figure, it has been found that Ra -

5 th International & 6 th All India Manufacturing Technology, Design and Research Conference (AIMTDR ) December th th,,..8 Figure Contribution of various input parameters for d of MMC. Conclusions. 66 v. Error 6.7 The results of study suggest that all input parameters have significant affect on Ra and d of MMC prepared by combining FDM, VM and SC process. As regards to Ra of MMC prepared the percentage of, and vacuum contributes.%,.97% and.96% respectively. Precise control at their level is required for optimum Ra value. The d of the final MMCs was also affected on any alteration made in levels of input parameters. The percentage contribution of input parameter was:.8%, -.8% and vacuum.% respectively. For optimum Ra the best settings were at 7.% mixed in Al, of 7 AFS number and.n/mm and for d was with % mixed in Al, of 7 AFS number and vacuum is controlled at. N/mm. 7%Si Alloy Castings Produced by VAEPC Process, Materials and Manufacturing Processes, Vol., pp Lee, C.W., Chua, C.K., Cheah, C.M., Tan, L.H. (), Rapid Investment Casting: Direct and Indirect Approaches Via Fused Deposition Modelling, International Journal of Advance Manufacturing Technology, Vol., pp.9. Singh, J. and Singh, R. (9), Investigations for statistically controlled rapid casting solution of lead alloys using three dimensional printing, Journal of Mechanical Engineering Sciences (Proc. of IMechE Part C), Vol., pp.-. Singh, R. (), Effect of work piece volume on statistically controlled rapid casting solution of aluminum alloys using three dimensional printing, Materials and manufacturing processes, Vol. 7, pp.77. Singh, R., Singh, J. and Singh, J. (), Macromodel for development of Al-AlO metal matrix composite with vacuum moulding: designed experiments, Journal of the Institution of Engineers (India): Series C, Vol.9, pp.-. Singh, R. (), Three dimensional printing for casting applications: A state of art review and future perspectives, Advanced Materials Research, Vol. 8-86, pp.-9. Singla, M., Divedi, D., Singh, L. and Chawla, V. (9), Development of aluminium based silicon carbide particulate metal matrix composite, Journal of minerals & materials characterization & engineering, Vol. 8, pp.7. Sood, A.K., Ohdar, R.K. and Mahapatra, S.S. (9), Improving dimensional accuracy of Fused Deposition Modelling processed part using grey Taguchi method, Journal of material and Science, Vol., pp.-. Acknowledgment: The authors are thankful to AICTE New Delhi for financial support. References Gaindhar, J.L., Jain, C.K. and Subbarathnanmaiah, K. (98), Effect of sand variables on dimensional accuracy of al-%cu alloy castings produced by v- process, Transactions of the American Foundry men's Society, Vol. 9, pp.. Kathiresan, K. and Sornar, K. (), Friction and wear studies of die cast aluminum alloy aluminum oxide-reinforced composites, Industrial Lubrication and Tribology, Vol. 6, pp.6 7. Kumar, P. and Gaindhar, J.L. (99), Off-line quality control for V-process castings, Quality and Reliability Engineering, Vol., pp.7 8. Kumar, S., Kumar, P. and Shan, H.S. (7), Effect of Process Parameters on the Solidification Time of Al- -