In this work, transformation behaviors and mechanical properties of cold-rolled shape memory alloy TisoNia9Fel by severe plastic deformation （SPD） were intensively investigated. The phase transformation behaviors, p...In this work, transformation behaviors and mechanical properties of cold-rolled shape memory alloy TisoNia9Fel by severe plastic deformation （SPD） were intensively investigated. The phase transformation behaviors, phase analysis, and microstructures were characterized by differential scanning calorimetry （DSC）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）, respectively. Tensile testing was performed to analyze the effect of SPD on the mechanical properties and shape memory of TisoNi49Fel alloy. When the thickness reduction is beyond 30 %, the martensitic transformation is suppressed. After cold-rolling, the alloy is mainly com- posed of B2 parent phases with some stress-induced martensitic B 19t phases, and high density of dislocations are generated and the grains are obviously refined. The yield stress ab significantly raises from 618 MPa of 0 % cold rolling to 1,338 MPa of 50 % SPD. Shape-memory effect increases from 6.5 % without cold rolling to 8.5 % after 30 % SPD, ascribed to the induced defects in cold rolling. Those results indicate that TisoNi49Fel alloy has improved mechanical properties and potential commercial applications after SPD.展开更多
This paper investigates the production of pure aluminum by using traditional metallurgy and nanotechnology. To make a pure aluminum stronger, extremely cold and mechanical manipulation process was employed and followe...This paper investigates the production of pure aluminum by using traditional metallurgy and nanotechnology. To make a pure aluminum stronger, extremely cold and mechanical manipulation process was employed and followed by carefully heat treatment cycle. The practical produetion and testing showed that the higher the stored dislocation＇s density after rolling was, the finer the recrystallized grains during heating were. In aluminum, these new grains were only a couple of nanometers in size, several hundred times smaller than the original crystals, making the aluminum much stronger than its original form.展开更多
基金supported by the National Natural Science Foundation of China (No. 50921003)the Industry, Education and Research Projects of the China Aviation Industrial (No. cxy2012BH04)
文摘In this work, transformation behaviors and mechanical properties of cold-rolled shape memory alloy TisoNia9Fel by severe plastic deformation （SPD） were intensively investigated. The phase transformation behaviors, phase analysis, and microstructures were characterized by differential scanning calorimetry （DSC）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）, respectively. Tensile testing was performed to analyze the effect of SPD on the mechanical properties and shape memory of TisoNi49Fel alloy. When the thickness reduction is beyond 30 %, the martensitic transformation is suppressed. After cold-rolling, the alloy is mainly com- posed of B2 parent phases with some stress-induced martensitic B 19t phases, and high density of dislocations are generated and the grains are obviously refined. The yield stress ab significantly raises from 618 MPa of 0 % cold rolling to 1,338 MPa of 50 % SPD. Shape-memory effect increases from 6.5 % without cold rolling to 8.5 % after 30 % SPD, ascribed to the induced defects in cold rolling. Those results indicate that TisoNi49Fel alloy has improved mechanical properties and potential commercial applications after SPD.
文摘This paper investigates the production of pure aluminum by using traditional metallurgy and nanotechnology. To make a pure aluminum stronger, extremely cold and mechanical manipulation process was employed and followed by carefully heat treatment cycle. The practical produetion and testing showed that the higher the stored dislocation＇s density after rolling was, the finer the recrystallized grains during heating were. In aluminum, these new grains were only a couple of nanometers in size, several hundred times smaller than the original crystals, making the aluminum much stronger than its original form.
