The dynamic mechanical response of SiC particulate reinforced 2024 aluminum matrix composites

doi:10.1016/j.matlet.2007.02.069

Materials Letters

Volume 61, Issues 23–24, September 2007, Pages 4606-4609

https://doi.org/10.1016/j.matlet.2007.02.069 Get rights and content

Abstract

The compression properties of the aluminum alloy 2024 metal matrix composites reinforced with 50 vol.% SiC particles were investigated using Instron testing machine and split Hopkinson pressure bar (SHPB) in this paper. The compression stress–strain curves were obtained at the strain rates ranging from 1 × 10^− 3 to 2.5 × 10³/s. The fracture surfaces were characterized by scanning electron microscopy. The results showed that SiCp/2024 Al composites exhibited high strain-rate sensitivity. The strength of composites tended to increase–decrease with increasing of strain rates. The effect of the strain rate on elongation was also discussed.

Introduction

Metal matrix composites (MMCs) such as Al, Ti and Ni alloys reinforced with Al₂O₃ or SiC particulates or whiskers have the potential to provide desirable mechanical properties including high specific stiffness, high plastic flow strength, creep resistance, good oxidation and corrosion resistance. These suites of properties make particles reinforced with MMCs attractive to a wide range of applications in the automobile, aerospace, civil engineering and military and other fields [1], [2], [3], [4]. In a wide range of engineering applications, MMCs may be subjected to dynamic loading. Hence, it is very necessary to understand the dynamic mechanical behavior of MMCs for use in practice and develop a specific constitutive model to characterize their deformation behavior for finite-element computational analysis.

Lots of work has been done on quasi-static and dynamic deformation of aluminum matrix reinforced within 30 vol.% or less volume fraction of SiC or Al₂O₃ particles. Razaghian et al. [5] have studied the fracture behavior of a composite based on 7075 Al reinforced with 15 vol.% SiC under uniaxial quasi-static tensile loading in temperature ranging from 25 to 400 °C; Wang et al. [6] have performed dynamic tensile test for 10 vol.% SiC particulate reinforced aluminum matrix composites at high strain rate; Li et al. [7], [8] studied the SiCp/Al composites compression properties at a strain rate range of 10^− 5–10⁵/s and dynamic shearing deformations by split Hopkinson torsion bar; Kalambur and Hall [9] indicated the dynamic compressive behavior of 25 vol.% SiCp/2024 Al composites; Perng et al. [10] indicated that the strength of the Al₂O₃ particle reinforced 6061 aluminum alloy composites increases with increasing of strain rate, but elongation of composites is insensitive to the strain rate. However, there is a large application of PR-MMCs with high reinforcement content in electric packaging such as in satellites due to its low heat expansion and high heat conductivity. And the metal matrix reinforced with high volume fraction (over 30 vol.%) of particle is seldom reported.

In the present work, the strain-rate sensitivity of composites containing 50 vol.% SiC particles was explored. The effect of strain rate and strain work on MMCs reinforced with the high volume fraction of SiC particles was investigated by using split Hopkinson pressure bar (SHPB) and Instron testing machine. The deformation mechanism of the SiCp/Al was also elucidated in this paper.

Section snippets

Materials and specimens

The aluminum alloy 2024 was chosen as the matrix and the reinforcement was the SiC particles with a mean size of 3 μm with heat retreat condition. The composites with 50 vol.% SiC content was produced by squeeze casting technology [11], [12]. The fabrication techniques involved the following processes: (1) fabrication and pre-heating of SiC particles preform; (2) melting of aluminum alloy; (3) infiltration of molten aluminum into SiC preform under pressure; (4) solidification of SiC/Al

Stress–strain curves

Fig. 1 illustrates the results of quasi-static and dynamic compression tests for the composites. It is evident that the strain rate has a significant effect on the overall strength SiCp/2024Al composite materials. For the tested composite materials, the flow stress at high strain rates increases considerably as compared to quasi-static loading. It can be noticed from the graph that sample stiffness and flow stress increase with the increase of strain rates ranging from 1250 to 2000/s and then

Conclusions

The compression properties of 50 vol.% SiCp/2024Al composite materials at different strain rates were obtained in this paper. The test results show that the strain rate has a considerable effect on the flow stress: The flow stress increases at strain rates ranging from 1250/s to 2000/s and then decreases at 2500/s and the elongation of the composites at high strain rate is larger than that under quasi-static loading.

SEM observation on the fracture surfaces shows that the crack particles can be

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The dynamic mechanical response of SiC particulate reinforced 2024 aluminum matrix composites

Abstract

Introduction

Section snippets

Materials and specimens

Stress–strain curves

Conclusions

Mater. Sci. Eng., A Struct. Mater.: Prop. Microstruct. Process.

Compos. Sci. Technol.

Mater. Sci. Eng., A Struct. Mater.: Prop. Microstruct. Process.

Int. J. Solids Struct.

Scr. Mater.

Mater. Sci. Eng., A Struct. Mater.: Prop. Microstruct. Process.

Mater. Sci. Eng., A Struct. Mater.: Prop. Microstruct. Process.

Mater. Lett.