Twin boundaries（TBs） are key factors influencing the mechanical properties of crystalline materials. We have investigated the intrinsic fatigue cracking mechanisms of TBs during the past decade. The effects of TB or...Twin boundaries（TBs） are key factors influencing the mechanical properties of crystalline materials. We have investigated the intrinsic fatigue cracking mechanisms of TBs during the past decade. The effects of TB orientations on the fatigue cracking mechanisms were revealed via cyclic deformation of a series of grown Cu bicrystals with a sole TB. Furthermore, the combined effects of crystallographic orientation and stacking fault energy（SFE） on the fatigue cracking mechanisms were clarified through cyclic deformation of polycrystalline Cu and Cu alloys. Both developments were reviewed in this report which will provide implications to optimize the interfacial design for the improvement of fatigue performance of metallic materials.展开更多
Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying ele...Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying elements and their impact on the twin boundary energy in aluminum.Alloying elements with small solubilities but strong interaction with twin boundary would significantly reduce twin boundary energies in aluminum at low temperatures.With increasing temperature,their segregation near twin boundary weakens,leading to their influence on twin boundary energies reduced.Some elements with large solubilities may greatly reduce the twin energies not only at low temperatures but also at high temperatures.Based on careful analysis of charge density and atomic radius,it has been found that chemical difference has little influence on twin boundary energy whereas the atomic size effect plays a leading role in causing the change of twin boundary energy.展开更多
基金supported by the National Natural Science Foundation of China (NSFC) under Grant Nos. 51471170, 51501197 and 51571198
文摘Twin boundaries（TBs） are key factors influencing the mechanical properties of crystalline materials. We have investigated the intrinsic fatigue cracking mechanisms of TBs during the past decade. The effects of TB orientations on the fatigue cracking mechanisms were revealed via cyclic deformation of a series of grown Cu bicrystals with a sole TB. Furthermore, the combined effects of crystallographic orientation and stacking fault energy（SFE） on the fatigue cracking mechanisms were clarified through cyclic deformation of polycrystalline Cu and Cu alloys. Both developments were reviewed in this report which will provide implications to optimize the interfacial design for the improvement of fatigue performance of metallic materials.
基金supported financially by the National Natural Science Foundation of China (Nos.51701243,11427806,51471067 and 51371081)the Hunan Provincial Natural Science Foundation of China (No.2019JJ40544)+3 种基金the Specialized Research Found for the Doctoral Program of Higher Education of China (No. 20120161110036)the National Basic Research (973) Program of China (No.2009CB623704)the PhD Research Startup Foundation of Central South University of Forestry and Technology (No. 2017YJ020)the supercomputer TH-1A installed at Hunan University
文摘Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying elements and their impact on the twin boundary energy in aluminum.Alloying elements with small solubilities but strong interaction with twin boundary would significantly reduce twin boundary energies in aluminum at low temperatures.With increasing temperature,their segregation near twin boundary weakens,leading to their influence on twin boundary energies reduced.Some elements with large solubilities may greatly reduce the twin energies not only at low temperatures but also at high temperatures.Based on careful analysis of charge density and atomic radius,it has been found that chemical difference has little influence on twin boundary energy whereas the atomic size effect plays a leading role in causing the change of twin boundary energy.
