Grain Size Effects on Mechanical Properties of Nanocrystalline Cu6Sn5 Investigated Using Molecular Dynamics Simulation

Abstract

Intermetallic compounds (IMCs) are inevitable byproducts during the soldering of electronics. Cu6Sn5 is one of the main components of IMCs, and its mechanical properties considerably influence the reliability of solder joints. In this study, the effects of grain size (8–20 nm) on the mechanical properties (Young’s modulus, yield stress, ultimate tensile strength (UTS), and strain rate sensitivity) of polycrystalline Cu6Sn5 were investigated using molecular dynamics simulations at 300 K and at a strain rate of 0.0001–10 ps−1. The results showed that at high strain rates, grain size only slightly influenced the mechanical properties. However, at low strain rates, Young’s modulus, yield stress, and UTS all increased with increasing grain size, which is the trend of an inverse Hall–Petch curve. This is largely attributed to the sliding and rotation of grain boundaries during the nanoscale stretching process, which weakens the interaction between grains. Strain rate sensitivity increased with a decrease in grain size.

The characterization of plastic behavior and mechanical properties in the gradient nanostructured copper

“…The box size was partitioned by the number of seeds to obtain the mean grain size, and the calculation was performed by considering the grain geometries as spherical volumes. 38,39 As mentioned before, the number of seeds was constant for all the samples. The grain orientation was also similar in the HNG and GNG structures.…”

Deformation and Force Chain of Two-Dimensional Granular Systems under Continuous Loading

“…Grain size has a certain effect on the mechanical properties of objects. Many scholars have studied the effects of particle size on the mechanical properties of objects [14][15][16]. Lakirouhani [17] studied the strength, physical, and engineering index parameters of dolomitic rocks with the same mineral composition but different grain size, found that there are significant positive correlations between grain size and uniaxial compressive strength, point load strength, Brazilian strength, and average Young's modulus.…”