The relationship between mechanical property and microstructure of NiTi shape memory alloy has been studied. It was founded that with increasing prestrain the memory recovery rate decreased, but the recovery stress an...The relationship between mechanical property and microstructure of NiTi shape memory alloy has been studied. It was founded that with increasing prestrain the memory recovery rate decreased, but the recovery stress and the recovery strain increased first and then decreased. The recovery stress and the recovery strain reached maximum at about 11% prestrain. The TEM(Transmission Electron Microscope) results of the alloy indicated that the microstructures with different prestrain of the alloy had obvious characters. At 9% prestrain, the martensite anamorphosis of the alloy still presented self-cooperation configuration, and some martensites have become thick obviously because of tropism. When the prestrain was 11%, the martensite anamorphosis has become completely thick and tropism became consistent. As the prestrain increased to 13%, the microstructures of the alloy have become disordered, the tropism became inconsistent and the interface became blurry.展开更多
This article explains the definition of pulmonary embolism as well as its causes and elaborates on a new type of inferior vena cava filter(VCF)we have developed. Shaped like a waistdrum, the VCF is mainly made of TiNi...This article explains the definition of pulmonary embolism as well as its causes and elaborates on a new type of inferior vena cava filter(VCF)we have developed. Shaped like a waistdrum, the VCF is mainly made of TiNi shape memory alloy-wire. It has a subulate wire frame which can intercept the thrombus on each side. Its medial body is made up of straight shape memory alloy-wire . Every pillar is bound by several shape memory alloy springs. This type of inferior vena cava filter has a good resistance to fatigue and is hard to be broken. Through animal experiments its framework has been proved to be lasting. Neither deformation nor fragmentation happened when the VCF had been kept in the body for a long time. The thrombus interception efficiency of our VCF is higher than imported VCFs. The filter is unfavorable for thrombosis. After implantation, the IVC was completely unimpeded and no displacement occurred. Moreover the VCF did little damage to the Wall of vein. Neither IVC perforation nor haematoma occurred after the operation.展开更多
文摘The relationship between mechanical property and microstructure of NiTi shape memory alloy has been studied. It was founded that with increasing prestrain the memory recovery rate decreased, but the recovery stress and the recovery strain increased first and then decreased. The recovery stress and the recovery strain reached maximum at about 11% prestrain. The TEM(Transmission Electron Microscope) results of the alloy indicated that the microstructures with different prestrain of the alloy had obvious characters. At 9% prestrain, the martensite anamorphosis of the alloy still presented self-cooperation configuration, and some martensites have become thick obviously because of tropism. When the prestrain was 11%, the martensite anamorphosis has become completely thick and tropism became consistent. As the prestrain increased to 13%, the microstructures of the alloy have become disordered, the tropism became inconsistent and the interface became blurry.
文摘This article explains the definition of pulmonary embolism as well as its causes and elaborates on a new type of inferior vena cava filter(VCF)we have developed. Shaped like a waistdrum, the VCF is mainly made of TiNi shape memory alloy-wire. It has a subulate wire frame which can intercept the thrombus on each side. Its medial body is made up of straight shape memory alloy-wire . Every pillar is bound by several shape memory alloy springs. This type of inferior vena cava filter has a good resistance to fatigue and is hard to be broken. Through animal experiments its framework has been proved to be lasting. Neither deformation nor fragmentation happened when the VCF had been kept in the body for a long time. The thrombus interception efficiency of our VCF is higher than imported VCFs. The filter is unfavorable for thrombosis. After implantation, the IVC was completely unimpeded and no displacement occurred. Moreover the VCF did little damage to the Wall of vein. Neither IVC perforation nor haematoma occurred after the operation.
