An Experimental Investigation on the Material Removal Rate and Surface Roughness of a Hybrid Aluminum Metal Matrix Composite (Al6061/SiC/Gr)

The objective of this paper was to determine the optimum process parameters of an electric discharge machine while machining a new hybrid aluminum metal matrix composite. In this study, a new hybrid aluminum metal matrix composite was prepared, with silicon carbide and graphite particles used as reinforcements, with the help of the stir casting method. The selected electric discharge machining parameters in this study were peak current (I), voltage (V), pulse-on time (Ton), and tool material, while the response parameters were material removal rate and surface roughness. To machine the fabricated samples, two different types of tool materials (copper and brass) were used as electric discharge machine electrodes, and each had a diameter (Ø) of 12.0 mm. The optimal settings of the electric discharge machining parameters were determined through experiments planned, conducted, and analyzed using the Taguchi (L18) technique. An analysis of variance and confirmatory tests were used to check the contribution of each machining parameter. It was found that the material removal rate increased with the increase in pulse-on time and pulse current, whereas the material removal rate decreased with the increase in voltage. On the other hand, reduced surface roughness could only be achieved when current, voltage, and pulse duration were low. It was also found that the selected electric discharge machining electrodes had a significant effect on both the material removal rate and the surface roughness.

Improvement and Optimization of the Hardness for the Aluminum Metal Matrix Composite Using Eggshell

This research examines the effect of size and weight fraction of the eggshell particles added on the hardening of the Al metal reinforced by eggshell Particles using the program MINITAB 16. Powder technology method has been used to produce a composite material, The composite material was obtained by adding different weight fractions (0,2, 6,10 and 12 wt. %) and the size (100,240,350,510and 670um) of eggshell particles to aluminum powder. It samples was composed by using pressing of single action then accompanied directly by process of sintering at 474°C under the inert gas effect conditions. it was concluded that the best hardening of (72.6971 Mpa) can be obtained when the variables were (Xi = 12 wt%) and (X2 =100um). The lights value of Xi and X2, obtained using the programs, was used in practice giving hardening (74Mpa) which it nearly similar to that obtained by program. Also results show that the variables weight fraction (X1) & Particle Size (X2) have a significant effect on hardening. Moreover, the hardening increases with increasing weight fraction. While hardening value decreases gradient with down eggshell particle size.

Wear and Friction Behavior of Gr/Sn Solid Lubricated Dual Reinforced AMCs

The current work has been undertaken to see the effect of Gr/Sn as a solid lubricant for the development of hybrid aluminum metal matrix composite (HAMCs). HAMCs were fabricated by reinforcing 10 wt. % (sillimanite + ilmenite) minerals with or without 1 wt. % Sn/Gr/both solid via stir casting technique. Optical microscopy revealed a homogenous distribution of reinforced particles with the refinement of silicon. Vicker hardness of the HAMCs showed a good interfacial bonding of particles with the matrix. The wear rate and coefficient of friction of the HAMCs are reduced with a maximum of composite with tin and graphite as lubrication agents. The composite contained tin and graphite wear rate as lubrication agents were in tune with the cast-iron brake drum used in the automobile industries. Abrasive wear was dominant at low loads and adhesive wear at high load, as confirmed from SEM analysis.

Microstructure And Mechanical Properties of Ultrasonically Processed Al-7Si Alloy / Y2O3 Nanocomposite

The aim of the present study is to investigate the microstructure and mechanical properties of the A356 aluminum metal matrix composite reinforced with Y2O3 particles. The composite is synthesized by adding 1 and 2 vol.% of reinforcement via stir casting assisted by ultrasonic treatment (UT). Microstructural contemplates shows improvement in the dispersion of nano Y2O3 particles and decrease in the porosity level due to the ultrasound aided synthesis. The UT refines the size of the Y2O3 particles as well as helps to improve its dispersion. The secondary dendrite arm spacing of 2 vol.% Y2O3 reinforced samples with 5 min UT is found to be significantly reduced to 12 µm as compared to that of the as-cast A356 alloy. Addition of 2 vol.% of nano Y2O3 has significantly improved the hardness of the A356 alloy from 60 HV to 108 HV. A considerable increment in the YS and TS of the A356 alloy is observed with the of Y2O3 and found to further improve with UT. However, small reduction in ductility is observed with the addition of Y2O3 as well as ultrasonic treatment.

Effect of Process Parameters on Mechanical Properties of Aluminum Composite Foam Developed by Friction Stir Processing

The underwater friction stir processing is used for development of aluminum metal matrix composite (AA2219-Y2O3) foam. For development of foam, holes with different diameter in the mid thickness of plate were filled with a mixture of TiH2 and aluminum powder and underwater friction stir processing was used to mix this mixture in aluminum metal matrix composite. Then precursors extracted from the processed zone and heated upto 650°C in a furnace for development of foam. The effect of diameter of hole, number of passes and the tool rotation direction has been studied on the foam cell size and static and dynamic compressive behavior of the foam. It is found that as the diameter of hole increases, the size of pores increases. The distribution of pores is better with higher number of passes and increasing the hole diameter. The quality of foam further improves by reversing the tool rotation direction. The developed foam has different pore size varies from 0.7 to 2.7 mm depends on the FSP parameters. Based on the size of pores and their distribution the relative density ranges from 0.1 to 0.78. The foam produced with 4 mm hole diameter has best static and dynamic compression properties.

Manufacture and characterization of aa6061 aluminum alloy metal matrix composites with ceramic particulate reinforcement

The work’s main objective was the manufacture of an AA6061 aluminum metal matrix composite reinforced with ceramics reinforcements of: aluminum oxide, silicon carbide, aluminum nitride and silicon nitride, through the powder metallurgy technique. The powders were subjected to high energy milling in a SPEX type vibrating mill. Thereafter, a cold uniaxial compactation was made and then the compacts were hot extruded. The powders were subjected to characterization using X-ray diffraction and laser diffraction granulometry. The extruded were characterized by scanning electron microscopy, energy dispersive spectroscopy and had their microhardness evaluated. The characteri-zation showed: the reinforcements’ addition in the matrix contributed to an acceleration of powders’ grinding; the reinforced samples had a higher microhardness than the unreinforced; it was observed that greater milling times and reinforcement’s addition increased the composites’ microhardness.

Mechanical properties of melt infiltration and powder metallurgy fabricated aluminum metal matrix composite

Metal foams have drawn an increasing interest especially in applications where weight and energy absorption are critical. Despite the extensive studies available on their characterization and enhanced fabrication techniques, limited work was found on the possibility of producing a porous composite foam. The objective of this article is to investigate two new synthesis techniques for manufacturing metal matrix composite foam that is, powder metallurgy and melt infiltration. Both techniques are studied using Sodium Chloride (NaCl) as a space holder in an aluminum-based metal matrix and graphene nanoparticles as reinforcements. The effect of the quantity added of both the space holder and graphene is studied using designed experiments. Although powder metallurgy provided lower baseline hardness, experimentation results suggest the superiority of the process over melt infiltration in terms of porosity and hardness. Results suggest that baseline aluminum hardness can be increased by up to 21.5% using powder metallurgy and 15% using melt infiltration. In terms of porosity, powder metallurgy porosity increased baseline more than ten folds while melt infiltration only doubled the baseline porosity. Moreover, it is easier to control the macroscopic shape, density, and distribution of the pores using powder metallurgy. It is also easier to disperse the reinforcement homogenously. Results will support several industries such as military, automotive, medical, and aerospace in developing this innovative material with superior properties and coping with their need for advanced applications.

Fabrication and Mechanical Properties of Hybrid Aluminum Metal Matrix Composite by Using Stir Casting Process

An attempt is made to study the influence of dispersion of Groundnut shell ash (GSA) on the hardness and density of Aluminum Metal Matrix Composite. It is an attempt to use agricultural waste in trying to enhance the mechanical properties of the already existing materials. The work deals with the use of groundnut shell ash, mixed with aluminum using stir casting process. . The composites with varying percentage of groundnut shell ash from 0% to 6% were prepared. The prepared specimens were tested before and after the heat treatment process in terms of its hardness using a Rockwell Hardness Tester. The present work attempts to compare the hardness and density of prepared composites as compared to the alloy. The comparison is carried out before and after the heat treatment process. The results indicate the increasing hardness value and reducing density of composites.