Diffusion bonding of TC21 titanium alloy was carried out at temperature ranging from 780 ℃ to 980 ℃ for 5-90 min.The interfacial bonding ratio,deformation ratio,microstructures and microhardness of the diffusion bon...Diffusion bonding of TC21 titanium alloy was carried out at temperature ranging from 780 ℃ to 980 ℃ for 5-90 min.The interfacial bonding ratio,deformation ratio,microstructures and microhardness of the diffusion bonded joints were investigated.Results show that joints with high bonding quality can be obtained when bonded at 880 ℃ for 15？30 min.The microhardness increases with increasing the bonding temperature,while it has a peak value（HV367） when bonding time is prolonged up to 90 min.Fully equiaxed microstructures,bi-modal microstructures and fully lamellar microstructures were observed when bonded in temperature range of 780-880 ℃,at 930 ℃ or 980 ℃,respectively.The volume fraction of α phase first increases and achieves the maximum when bonded at 880 ℃ for 60 min,and then descended.展开更多
The morphologies, sizes, compositions and volume fractions of dendritic phases in in situ Ti-based metallic glass matrix composites （MGMCs） containing beryllium （Be） with the nominal composition of Tia7Zr19Cu5V12B...The morphologies, sizes, compositions and volume fractions of dendritic phases in in situ Ti-based metallic glass matrix composites （MGMCs） containing beryllium （Be） with the nominal composition of Tia7Zr19Cu5V12Be17 （mole fraction, %） were investigated using XRD, SEM, EBSD, TEM, EDS and three-dimensional reconstruction method. Moreover, visualized at the nanoscale, Be distribution is confirmed to be only present in the matrix using scanning transmission electron microscopy-electron energy loss spectroscopy （STEM-EELS）. Based on these findings, it has been obtained that the accurate chemical compositions are Wi28.3Zr19.7Cu8V6.4Be37.6 （mole fraction, %） for glass matrix and Wi62.nZr18.aCu2.6V16.6 （mole fraction, %） for the dendritic phases, and the volume fractions are 38.5% and 61.5%, respectively. It is believed that the results are of particular importance for the designing of Be-containing MGMCs.展开更多
基金Project(2004CB619201)supported by the National Basic Research Program of ChinaProject(50621063)supported by the National Natural Science Foundation of China
基金Project(2010CB731704)supported by the National Basic Research Program of Chinathe Northwest Institute for Non-ferrous Metal Research of China for the support
文摘Diffusion bonding of TC21 titanium alloy was carried out at temperature ranging from 780 ℃ to 980 ℃ for 5-90 min.The interfacial bonding ratio,deformation ratio,microstructures and microhardness of the diffusion bonded joints were investigated.Results show that joints with high bonding quality can be obtained when bonded at 880 ℃ for 15？30 min.The microhardness increases with increasing the bonding temperature,while it has a peak value（HV367） when bonding time is prolonged up to 90 min.Fully equiaxed microstructures,bi-modal microstructures and fully lamellar microstructures were observed when bonded in temperature range of 780-880 ℃,at 930 ℃ or 980 ℃,respectively.The volume fraction of α phase first increases and achieves the maximum when bonded at 880 ℃ for 60 min,and then descended.
基金Project(11374028)supported by the National Natural Science Foundation of ChinaProject supported by the Cheung Kong Scholars Program of China
文摘The morphologies, sizes, compositions and volume fractions of dendritic phases in in situ Ti-based metallic glass matrix composites （MGMCs） containing beryllium （Be） with the nominal composition of Tia7Zr19Cu5V12Be17 （mole fraction, %） were investigated using XRD, SEM, EBSD, TEM, EDS and three-dimensional reconstruction method. Moreover, visualized at the nanoscale, Be distribution is confirmed to be only present in the matrix using scanning transmission electron microscopy-electron energy loss spectroscopy （STEM-EELS）. Based on these findings, it has been obtained that the accurate chemical compositions are Wi28.3Zr19.7Cu8V6.4Be37.6 （mole fraction, %） for glass matrix and Wi62.nZr18.aCu2.6V16.6 （mole fraction, %） for the dendritic phases, and the volume fractions are 38.5% and 61.5%, respectively. It is believed that the results are of particular importance for the designing of Be-containing MGMCs.
