Madeva Nagaral

Dry Sliding Wear Behavior of Graphite Particulate Reinforced Al6061 Alloy Composite Materials

This present paper is an investigation made to study the un-lubricated sliding wear behavior of Al6061 alloy composites reinforced with graphite particulates of size 100-125 μm. The content of graphite in the alloy was varied from 6-9% in steps of 3 wt. %. The liquid metallurgy technique was used to fabricate the composites. A pin-on-disc wear testing machine was used to evaluate the volumetric wear loss, in which a hardened EN32 steel disc was used as the counter face. The results indicated that the volumetric wear loss of the composites was lesser than that of the Al6061 matrix alloy and it further decreased with the increase in graphite content up-to 6 wt.%. For composites containing 9 wt. % of graphite particulates, the volumetric wear loss was more than that of 6wt. % composites, but lesser than base matrix alloy. However, the material loss in terms of wear volume increased with the increase in load and sliding speed, both in case of composites and the alloy.

Microstructure and Mechanical Properties of Al6061-Graphite Composites Fabricated by Stir-Casting Process

In the present study, the experimental results of the mechanical properties of Al6061-Graphite composites presented. The composites containing 6 to 9 wt% of graphite in steps of 3 wt% were prepared using liquid metallurgy route in particular stir casting technique. For each composite, reinforcement particles were preheated to a temperature of 250°C and then dispersed in steps of two into the vortex of molten Al6061 alloy to improve the wettability and distribution. Microstructural characterization was investigated by optical and scanning electron microscopy. Tensile and hardness tests were carried out in order to identify mechanical properties of composites. The results of microstructural study revealed uniform distribution of graphite particles and low porosity in micro composite specimens.The results of this study revealed that as graphite percentage was increased, there was significant increase in ultimate tensile strength, yield strength and ductility, accompanied by a nominal drop in the hardness of the material

Effect of SiC and Graphite Particulates Addition on Wear Behaviour of Al2219 Alloy Hybrid Composites

In this investigation wear behaviour of A12219 alloy reinforced with SiC and graphite particulates were studied. The percentage of silicon carbide and graphite as reinforcements were varied from 2 wt.% to 4 wt.% in steps of 2. Energy dispersive spectroscopy and scanning electron microphotographs were used to confirm the presence of SiC and graphite particulates and its uniform distribution over the aluminum matrix. Wear behaviour of aluminum alloy Al2219 reinforced with silicon carbide and graphite fabricated by stir casting process was investigated. The wear properties of the metal matrix composites were studied by performing dry sliding wear test using a pin-on-disc wear tester. The experiments were conducted at a constant sliding velocity of 1.73m/s over a load of 2kg. The results showed that the wear resistance of Al2219-2%SiC-2% graphite and Al2219-4%SiC-4% graphite composites were better than the unreinforced alloy. The wear in terms of weight loss and wear rate was found to decrease with the increasing the weigh percentages of SiC and graphite. To study the dominant sliding wear mechanism worn surfaces were analyzed using scanning electron microscopy.

Evaluation of wear properties of TiC particulates reinforced Al2219 alloy composites

In the present study, Al2219 – 2, 4 and 6 wt. % of TiC metal matrix composites were synthesized by Stir casting method. Microstructural analysis of Al2219-TiC composites was performed by using scanning electron microscopy. Microstructural characterization of the developed TiC particulates reinforced composites revealed uniform distribution of micro size TiC particulates in the base matrix. The wear resistance of metal matrix composites was studied by performing dry sliding wear test using a pin on disc apparatus. The experiments were conducted at a constant sliding speed of 600rpm and sliding distance of 2000m over a varying load of 0.5kg, 1kg, 1.5kg and 2kg. Similarly experiments were conducted at a constant load of 1kg and sliding distance of 2000m over a varying sliding speed of 600, 700, 800 and 900rpm. The results showed that the wear resistance of Al2219 - TiC composites was better than the unreinforced alloy. The wear rate was found to increase with the load and sliding speed. To study the dominant...