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Engineering Science in
Additive Manufacturing EST manipulates structure of Ti-6Al-4V/Cu

A B

C

Figure 10. Schematic representation of microstructure evolution during EST. (A) Original sample; (B) EST process; (C) cooled sample.
Abbreviation: EST: Electroshock treatment.

Figure 9E displays the shear engineering stress-strain 3.4. Effect mechanism of EST on Ti-6Al-4V/Cu-Cr-Zr
curve of the Ti-6Al-4V/Cu-Cr-Zr composite. After EST, The microstructural evolution of MBZ related to EST
the shear strength and strain curve exhibited significant is shown in Figure 10, and the potential mechanism
changes. The EST-0 sample achieved a shear strength of for the mechanism is proposed. EST can lead to a
80 MPa with an elongation of 12.35%. The reaction layer significant increase in the elongation of Ti-6Al-4V/
formed at the interface ensures a strong bond between Cu-Cr-Zr because the pressure and high temperature
the Ti-6Al-4V coating and the Cu-Cr-Zr substrate. during EST results in the significant plastic deformation
Concurrently, the Cu-Cr-Zr matrix exhibits excellent of the Ti-6Al-4V coating, which promotes the physical
toughness and plasticity, enabling deformation-induced elimination of porosity at the bonding zone, as shown in
resistance to external loads and thereby enhancing Figure 10A and B. This process helps repair microscopic
the overall toughness and plasticity of the Ti-6Al-4V/ defects at the interface, thereby enhancing the material’s
Cu-Cr-Zr composite. Following EST, both shear mechanical properties.
strength and elongation of the Ti-6Al-4V/Cu-Cr-Zr
composite increased to varying degrees. The maximum As shown in Figure 10C, EST promotes the dissolution
increase occurred at a current density of 205 A/mm of precipitates and accelerates recrystallization in the MBZ
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(EST-1 sample), achieving a shear strength of 132 MPa of Ti-6Al-4V/Cu-Cr-Zr. With increasing temperature,
and an elongation of 36.75%. Both shear strength and thermal activation enhanced atomic diffusion and reaction
elongation exhibited an initial increase followed by a kinetics. However, the interdiffusion behavior between Ti
decrease across different current densities applied in and Cu in the MBZ was greatly impacted. Diffusion of Cu
EST. Comparing samples processed at varying current atoms in the MBZ favored the stabilization of the β phase
densities revealed that intergranular nano-precipitates during cooling. The solid-state diffusion of Ti in the MBZ
play a crucial role in enhancing material strength and was suppressed, obviously, and an unbalanced mass flux
promoting dislocation activity, thereby improving between Ti and Cu occurred. Finally, a continuous α phase
plasticity. These intergranular nano-precipitates was formed on the surface. However, due to the small
comprise multiple phases with distinct structures. The radius of the Cu atoms, the Cu atoms continued to diffuse
well-matched crystal planes favorable for dislocation slip through the grain boundaries into the reactive layer, and
enable continuous slip across different phase structures. the Cu Ti phase might further capture Cu to promote its
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Following EST, the shear strength and elongation of growth. The use of coherent intracrystalline precipitates
the samples significantly surpassed those of untreated to impede dislocation motion can enhance the strength
specimens. This demonstrates that adjusting current of the material. In addition, activation of mechanisms,
density effectively improves mechanical properties, such as laminar dislocations and deformation can
though beyond a certain threshold, the effect becomes also enhance material properties. Under high-density
counterproductive. current conditions, Ti Cu precipitates in the MBZ and
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Volume 1 Issue 4 (2025) 12 doi: 10.36922/ESAM025430030