A multiscale experimental analysis of mechanical properties and deformation behavior of sintered copper\u2013silicon carbide composites enhanced by high-pressure torsion

Szymon Nosewicz,Malgorzata Lewandowska,Marcin Chmielewski,Piotr Bazarnik,Melanie Clozel,Barbara Romelczyk-Baishya,Zbigniew Pakieła,Yi Huang,Łukasz Kurpaska,Piotr Jenczyk,Terence G Langdon,Dariusz Jarząbek

doi:10.1007/s43452-021-00286-4

Abstract

Experiments were conducted to investigate, within the framework of a multiscale approach, the mechanical enhancement, deformation and damage behavior of copper–silicon carbide composites (Cu–SiC) fabricated by spark plasma sintering (SPS) and the combination of SPS with high-pressure torsion (HPT). The mechanical properties of the metal–matrix composites were determined at three different length scales corresponding to the macroscopic, micro- and nanoscale. Small punch testing was employed to evaluate the strength of composites at the macroscopic scale. Detailed analysis of microstructure evolution related to SPS and HPT, sample deformation and failure of fractured specimens was conducted using scanning and transmission electron microscopy. A microstructural study revealed changes in the damage behavior for samples processed by HPT and an explanation for this behavior was provided by mechanical testing performed at the micro- and nanoscale. The strength of copper samples and the metal–ceramic interface was determined by microtensile testing and the hardness of each composite component, corresponding to the metal matrix, metal–ceramic interface, and ceramic reinforcement, was measured using nano-indentation. The results confirm the advantageous effect of large plastic deformation on the mechanical properties of Cu–SiC composites and demonstrate the impact on these separate components on the deformation and damage type.

Highlights

Metal–matrix composites (MMCs) are an important class of materials in which the microstructure can be tailored to have superior properties by comparison with the non-reinforced alloys, including: enhanced high-temperature performance, high specific strength and stiffness, increased wear resistance, better thermal and mechanical fatigue and creep resistance
Processing by high-pressure torsion (HPT) leads to a significant change in the Cu and Cu–SiC composites
scanning electron microscope (SEM) imaging did not reveal any additional phases in the Cu–SiC composite structure which may be formed during the spark plasma sintering (SPS) processing

Summary

Introduction

Metal–matrix composites (MMCs) are an important class of materials in which the microstructure can be tailored to have superior properties by comparison with the non-reinforced alloys, including: enhanced high-temperature performance, high specific strength and stiffness, increased wear resistance, better thermal and mechanical fatigue and creep resistance. Due to their possible applications in the aerospace, automotive, defense and general engineering industries, which require durability and long-term performance, the mechanical behavior of the MMCs is a crucial issue dominating their development. SPD procedures have been developed to refine the grain size in metals down to the ultrafine regime below 1 μm and thereby to enhance the mechanical strength [7]

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Conclusion