Experimental investigation on fracture toughness of Al6061–graphite by using Circumferential Notched Tensile Specimens

Abstract

ABSTRACT. This paper presents the experimental work carried out on the fracture behavior of aluminium 6061 (Al6061) and graphite particulate composites. The required specimens are prepared using stir casting method with graphite proportions ranging from 3 to 12 % by weight. The fracture behavior of Al6061-graphite particulate composites produced using stir casting method, was investigated by conducting experiments on Universal Testing Machine (UTM). Circumferential Notched Tensile (CNT) specimens were utilized to evaluate the fracture toughness of the composites. From the experiment the fracture toughness KIC= 15.85MPa m 1/2 is obtained for Al6061-9% Graphite. Further, the experimental results revealed that, except 12% graphite, the fracture toughness of Al6061-graphite was observed to increases with an increase in weight percentage of graphite. The experimental results reinforce that Al6061-graphite particulate MMCs are suitable for automotive and aerospace applications requiring high fracture toughness apart from good wear resistance.

Fracture toughness investigations of Al6061-Graphite particulate composite using compact specimens

“…This increment is due to the effect of increased graphite particulates which block the initiation of internal cracks in the microstructure. This increment in KIc is consistent with the trend in most as-cast Al based particulate reinforced composites [7,8,12,14]. The decrement of fracture toughness at 12% graphite may be an effect of increased graphite particles which causes particle clustering in the surrounding matrix.…”

“…rocessing of MMCs was done by the stir casting technique [8]. Aluminium 6061-graphite specimens were prepared at varied weight fractions of graphite (3%, 6%, 9%, and 12%) using stir casting method.…”

“…Mechanical characterization such as tensile strength and elongation experiments by using Universal Testing Machine [4,5] (UTM) of Al/SiC has been reported for a varying mass fraction of SiCp with Aluminium. Fracture toughness [6], tensile fracture behavior [7,8,9] on Circumferential Notched Tensile (CNT) specimens and Compact Tension (CT) test [10,11] specimen of Al alloy with different reinforcements, fracture toughness by indentation techniques [12,13] were studied by different researchers. Most of them compared their results with the unreinforced aluminium alloy.…”

Not available

“…Considering the brittle behavior of this material, brittle fracture is a typical failure mechanism which usually happens after the initiation of micro-cracks in the most stressed parts of the structure, combined in some cases with a negligible amount of plasticity [1][2][3][4]. The majority of the studies focused on structural integrity of graphite components have been devoted to the investigation of cracked components by quantifying the fracture toughness under prevalent mode I loading [5][6][7]. Innovative techniques have been proposed in the literature for fracture assessment of isotropic graphite under mode I loading [8][9][10].…”

Effect of addition of SiC particles on the Microstructure and Hardness of Al-SiC composite

“…Various authors have studied the mechanical properties of the as-cast aluminum graphite composites [3][4][5][6][7] for various reinforcement compositions. The results show that mechanical properties like hardness and tensile properties increase with the increment in the graphite.…”