Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into commo...Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into common brasses by casting.SEM and EDS were used to analyze the microstructure of graphite brasses,and the relationship between the microstructure and machinability was investigated.The results show that graphite particles are formed by the decomposition of cementite particles in cast brasses.The graphite particles are uniformly dispersed in the brass matrix with the average size of 5.0 μm and the volume fraction of ~1.1%.The machinability in the graphite brass is dramatically increased relative to the common brass,because of the lubricating properties of graphite particles and its role in chip breaking.The workpiece surface of the graphite brasses chips is smooth and burr-free,and the chips of graphite brasses are short（C-shape） and discontinuous,which is much better than that of the long spiral chips of common brasses.展开更多
Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle siz...Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle size of iron ore resulted in better gamma radiation protection owing to more homogenous distribution. In addition, the materials had flexible properties up to the addition of 60 wt% iron ore content. Further, 0.5 mm Pb E gamma protection was provided by using 2.06-mm-thick SDT-60 as the Co-60 source. Iron ore–silicone rubber composites are candidate materials for lead-free flexible radiation protection systems owing to their relatively inexpensive and easy production.展开更多
This article summarizes the developing situation of environmentally friendly copper alloy at home and abroad,focusing on developing situation of silicon phosphorus brass. It is considered that this series of alloy is ...This article summarizes the developing situation of environmentally friendly copper alloy at home and abroad,focusing on developing situation of silicon phosphorus brass. It is considered that this series of alloy is a good low-cost environmentally friendly alloy based on rich element. It has important application prospect in sanitary system and is an important revolution made to lead brass material which has been used for a long period in history.展开更多
基金Projects(51271090,51364036,51471083)supported by the National Natural Science Foundation of ChinaProject(IRT0730)supported by the Program for Changjiang Scholars and Innovative Research Team in University,China+1 种基金Project(NCET-10-0184)supported by the Program for New Century Excellent Talents in University,ChinaProject(20103601110001)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into common brasses by casting.SEM and EDS were used to analyze the microstructure of graphite brasses,and the relationship between the microstructure and machinability was investigated.The results show that graphite particles are formed by the decomposition of cementite particles in cast brasses.The graphite particles are uniformly dispersed in the brass matrix with the average size of 5.0 μm and the volume fraction of ~1.1%.The machinability in the graphite brass is dramatically increased relative to the common brass,because of the lubricating properties of graphite particles and its role in chip breaking.The workpiece surface of the graphite brasses chips is smooth and burr-free,and the chips of graphite brasses are short（C-shape） and discontinuous,which is much better than that of the long spiral chips of common brasses.
文摘Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle size of iron ore resulted in better gamma radiation protection owing to more homogenous distribution. In addition, the materials had flexible properties up to the addition of 60 wt% iron ore content. Further, 0.5 mm Pb E gamma protection was provided by using 2.06-mm-thick SDT-60 as the Co-60 source. Iron ore–silicone rubber composites are candidate materials for lead-free flexible radiation protection systems owing to their relatively inexpensive and easy production.
文摘This article summarizes the developing situation of environmentally friendly copper alloy at home and abroad,focusing on developing situation of silicon phosphorus brass. It is considered that this series of alloy is a good low-cost environmentally friendly alloy based on rich element. It has important application prospect in sanitary system and is an important revolution made to lead brass material which has been used for a long period in history.
