Microstructure Evolution and Mechanical Stability of Supersaturated Solid Solution Co-Rich Nanocrystalline Co-Cu Produced by Pulsed Electrodeposition.

Killang Pratama,Jenifer Barrirero,Christian Motz,Frank Mücklich

doi:10.3390/ma13112616

Killang Pratama, Jenifer Barrirero + Show 2 more

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https://doi.org/10.3390/ma13112616

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Journal: Materials	Publication Date: Jun 8, 2020
Citations: 7	License type: CC BY 4.0

Affiliation: Saarland University, Bandung Institute of Technology

Abstract

Thick films of supersaturated solid solution nanocrystalline Co-Cu (28 at.% Cu) were synthesized through the pulsed electrodeposition technique. Microstructural changes of nanocrystalline Co-Cu were intensively studied at various annealing temperatures. Annealing at 300 °C results in a spinodal decomposition within the individual grains, with no grain coarsening. On the other hand, distinct phase separation of Co-Cu is detected at annealing temperatures beyond 400 °C. Static micro-bending tests show that the nanocrystalline Co-Cu alloy exhibits a very high yield strength and ductile behavior, with no crack formation. Static micro-bending tests also reported that a large plastic deformation is observed, but no microstructure change is detected. On the other hand, observation on the fatigue resistance of nanocrystalline Co-Cu shows that grain coarsening is observed after conducting the cyclic micro-bending test.

Highlights

Studies on the fundamental behavior [1], mechanical properties [2], and possible industrial applications [3] of nanocrystalline materials are wide-spread in the literature
Investigations into the thermal stability and microstructure evolution of nanocrystalline Co-Cu have been performed in previous works, mostly at temperatures beyond 400 ◦ C [6,7,8], but more research about microstructural changes at lower temperatures is required
atom probe tomography (APT) showed that spinodal decomposition of Co-Cu system could start at a low annealing temperature

Summary

Introduction

Studies on the fundamental behavior [1], mechanical properties [2], and possible industrial applications [3] of nanocrystalline materials are wide-spread in the literature. Among of the promising materials in this class are supersaturated solid solution nanocrystalline alloys, e.g., Co-Cu alloy, the microstructure and phase distribution of which can be modified by annealing treatments, to enhance thermal and mechanical stability, as well as tailoring physical properties [4,5]. The information about the mechanical properties of single-phase nanocrystalline Co and Cu is widely available in the literature [12,13,14,15,16,17]. More research on the mechanical properties of nanocrystalline Co-Cu with different microstructures is required

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