Effect of shock-wave loading on the internal microstructure and mechanical properties of fine-grained copper

Abstract

It is shown that preloading of fine-grained copper with a the grain size of 0.5 m by a shock wave of intensity ≈ 25-50 GPa does not lead to changes in its internal microstructure and mechanical properties, and the dislocation density increases only slightly from 1.8 · 10 11 cm −2 in the initial state to (3.1-3.6) · 10 11 cm −2 after shockwave loading. An increase in shock wave intensity to pressures > 55 GPa leads to a decrease in the dislocation density to 2.5 · 10 9 cm −2 , an increase in the grain size to ≈19 µm, the occurrence of microtwins inside the grains, and a reduction in the mechanical properties of fine-grained copper to the level of coarse-crystalline copper.

The Effect of Blast Exposure Distance on Hardness and Reduced Modulus Properties of Lead-Free Solder

“…The shortest distance from the blast source gave a high impact on the degradation of hardness properties compared to others. This result was in agreement with the work reported by Ignatova et al [8], who found that exposure to shock wave leads to decrease the dislocation density and the increase in grain size. According to Tang et al [12], less content of Ag in SAC solder resulted in an enlargement of β-Sn grain.…”

“…The reliability of solder interconnects is related to its mechanical properties. A study done by Ignatova et al [8] found that the dislocation and mechanical properties of fine copper metal reduced after exposure to shock wave. However, Kulkov et al [9] found that the value of the hardness and yield strength of aluminum alloy was increased after the exposure to the shock wave.…”

Effect of Blast Wave on Intermetallics Formation, Hardness and Reduced Modulus Properties of Solder Joints

“…The decrease in hardness value after blast test was correlated to the coarsening of β-Sn phase and the particle of IMC in bulk solder. This results was in agreement with the work reported by Ignatova et al [15], who found that exposure to shock wave lead to decrease the dislocation density and increase in grain size. According to Tang et al [16], less content of Ag in SAC solder resulted in an enlargement of β-Sn grain.…”

Correlation of microstructural evolution and hardness properties of 99.0Sn-0.3Ag-0.7Cu (SAC0307) lead-free solder under blast wave condition

“…Tan et al (2017) stated that coarsening of β -Sn phase and the formation of Cu 6 Sn 5 whiskers in the eutectic region may have reduced the resistance of the solder matrix against indentation force and resulted in a lower solder matrix hardness. Ignatova et al (2010) found that the increase in shock wave intensity (pressure) leads to a decrease in dislocation density. In addition, the grain size increases because of the increasing intensity of the shock wave and the reduction in the mechanism of fine-grained copper to the level of coarse crystalline copper.…”