Experimental investigation of fracture toughness in Al 356-SiCp aluminium matrix composite

Abstract

The developed aluminum matrix composite (AMC) is considered to be a promising material for low and high-temperature applications. Fiber reinforced AMC materials have high specific strength and modules of elasticity, together with excellent heat resistance. This experimental investigation was initiated to study the low-toughness fracture in Al 356-SiCp (silicon carbide particles) with respect to the role of the various elements of the microstructure and their probable contribution. The fracture in this composite is studied experimentally, in terms of fracture toughness testing. The low-toughness fracture is believed to be an inherent property of this composite and is caused mainly by the differential elastic and thermal properties of the two constituents. These differentials degrade the matrix alloy near the interface by its strain hardening capacity and by stress intensification introduced by the SiC particle geometry. Consequently, the matrix near the interface is subjected to high localized damage leading to premature fracture. It is found that the matrix alloy controls both flow properties and fracture in the materials investigated. It is concluded that a higher toughness composite requires a proper choice of constituent properties which dominate the stress state at the interface.

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.…”

“…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.…”

Characterization of hybrid aluminum matrix composites for advanced applications – A review

“…The results are in line with those obtained by Alaneme et al [26], who determined the fracture toughness values of hybrid composites by circumferential notched tensile (CNT) specimens. In this study, load-extension plots were used to evaluate the fracture toughness of the composites [50,51]. The hybrid composites containing 2 wt.% and 3 wt.% RHA contents possessed higher fracture toughness values as compared to the ceramics reinforced composite [26].…”

Experimental and finite element analysis of mechanical and fracture behavior of SiC particulate filled A356 alloy composites: Part I

“…At the interface of Cu/Al 2 O 3 composite, the crack propagation was due to high level of tensile thermal stresses inside the metallic phase as well as low contiguity of ceramic phase. However, Ranjbaran 15 carried out an experiment to study the fracture toughness of Al356-SiCp aluminum matrix composite and determined that the low fracture toughness is believed to be an inherent property of this composite and is caused primarily by the difference in elastic and thermal properties of the two constituents. Prabu et al 16 reported the influence of volume fraction of SiC and diameter of the fiber on interfacial stress/strain characteristics of 6061 Al/SiC MMCs in finite element analysis (FEA) method and found that the fiber diameter plays an important role in the debonding and the debonding is more prominent in the interfacial element near the axis of symmetry.…”