Samigullina A A, Mukhametgalina A A, Sergeyev S N, Zhilyaev A P, Nazarov A A, Zagidullina Yu R, Parkhimovich N Yu, Rubanik V V, Tsarenko Yu V
Institute for Metals Superplasticity Problems, Russian Academy of Sciences, 39 Khalturin Str., 450001 Ufa, Russia.
Institute for Metals Superplasticity Problems, Russian Academy of Sciences, 39 Khalturin Str., 450001 Ufa, Russia; Bashkir State University, 32 Zaki Validi Str., 450076 Ufa, Russia.
Ultrasonics. 2018 Jan;82:313-321. doi: 10.1016/j.ultras.2017.09.005. Epub 2017 Sep 15.
Commercially pure nickel was processed by high pressure torsion (HPT) and subjected to ultrasonic treatment (UST) with different amplitudes of compression-tension stresses in the zone of stress antinode of a standing wave. It was found that microstructure parameters such as the dislocation density, low- and high-angle grain boundary fractions, microhardness, and the stored excess energy as well, non-monotonically depend on the ultrasound amplitude. A structure relaxation leading to a reduction of internal stresses and stored energy and increase of the fraction of high-angle boundaries was observed at some intermediate amplitudes of the oscillating stress. The maximum relaxation effect was observed in the samples after UST with the amplitude of 60MPa. Possible mechanisms of the influence of ultrasound on the microstructure of deformed materials are discussed.
对工业纯镍进行高压扭转（HPT）处理，并在驻波应力波腹区域施加不同压缩-拉伸应力幅值的超声处理（UST）。结果发现，诸如位错密度、低角度和高角度晶界分数、显微硬度以及储存的多余能量等微观结构参数，并非单调地依赖于超声幅值。在振荡应力的某些中间幅值下，观察到结构弛豫，这导致内应力和储存能量降低，高角度晶界分数增加。在超声幅值为60MPa的样品中观察到最大弛豫效应。讨论了超声对变形材料微观结构影响的可能机制。
