Softening of the elastic modulus in submicrocrystalline copper

Effects of grain size and temperature on mechanical response of nanocrystalline copper

“…In addition, at lower temperatures, the Young's modulus has larger values, except for d ¼3 nm. This is because the grain growth occurs due to the thermal effect following the equilibration process at 300 K. Neglecting the data for d ¼3 nm, we measured the temperature dependence of Young's modulus and obtained a value of À 37 MPa/K, which is close to the experimental value ( À 40 MPa/K) reported for the same material with a grain size of 200 nm [37]. Further, in comparison with other simulation results using 3D systems [14,33,38], the Young's modulus in our system is higher by approximately þ10 GPa at 300 K. Therefore, the quasi-2D system has strong stiffness.…”

An ultrasonic internal friction study of ultrafine-grained AZ31 magnesium alloy

“…Nevertheless, compared with the increase of the Q À1 s for the examined materials upon heating reported in the next paragraph, the differences between the individual materials at the room temperature are rather negligible. There is also a weak systematic decrease of the Young's modulus by the individual passes of ECAP seen in Table 2, which is in agreement with the observations of elastic softening of other ECAPed materials reported in literature (e.g., [39]). …”

Studying the elastic properties of nanocrystalline copper using a model of randomly packed uniform grains

“…, and blue (CNA calculation, fitted) lines are from this study; the cyan circle [13] represents another simulation data; the yellow squares [37], red squares [35,36], orange square [4], and blue square [16] show data from experimental studies; the dashed line represents the coarse-grained limit [39]. Color bars associated with the experimental data show projected values of the moduli at 300 K by considering the temperature-dependence (À40 MPa/K) observed experimentally [38], if the original data were not obtained at this temperature. Color bar associated with the cyan simulation data shows the offset radius d CN , because grain boundary thickness is not taken into account in that study.…”