A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging...A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging machine was reached by a constant pushing force. The deformation of grooves in pipe reduced section during rotary swaging was analyzed. The shrinkage and extensibility of pipe reduction were measured and calculated. Furthermore, four aspects, including outer diameter, surface roughness, extensibility and processing time of pipe reduction, which were influenced by the pushing force, were considered. The results show that the tube wall thickness increases gradually along the z-axis at sinking section. However, the outer diameters, surface roughness and micro-cracks at reduced section tend to decrease along the z-axis. Besides, the effect of variation in the pushing force on the extensibility is limited while an increase in the pushing force results in a decrease of surface roughness. Therefore, a large pushing force within the limit is beneficial to pipe reduction manufacturing during rotary swaging process.展开更多
Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical propert...Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.展开更多
The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a f...The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a friction force at the contact surface between the tube and the tool occurs. In guiding zone, the friction coefficients between tube and die can be estimated from the measured axial feeding forces. In expansion zone, the friction coefficients between tube and die can be evaluated from the measured geometries of expanded tubes and FE analysis.展开更多
基金Project (U0834002) supported by the Key Program of NSFC Guangdong Joint Funds of ChinaProjects (51005079, 20976055) supported by the National Natural Science Foundation of China+1 种基金Project (10451064101005146) supported by the Natural Science Foundation of Guangdong Province, ChinaProject (20100172120001) supported by Specialized Research Fund for the Doctoral Program of Higher Education, China
文摘A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging machine was reached by a constant pushing force. The deformation of grooves in pipe reduced section during rotary swaging was analyzed. The shrinkage and extensibility of pipe reduction were measured and calculated. Furthermore, four aspects, including outer diameter, surface roughness, extensibility and processing time of pipe reduction, which were influenced by the pushing force, were considered. The results show that the tube wall thickness increases gradually along the z-axis at sinking section. However, the outer diameters, surface roughness and micro-cracks at reduced section tend to decrease along the z-axis. Besides, the effect of variation in the pushing force on the extensibility is limited while an increase in the pushing force results in a decrease of surface roughness. Therefore, a large pushing force within the limit is beneficial to pipe reduction manufacturing during rotary swaging process.
文摘Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.
基金supported by grants-in-aid for the National Core Research Center Program from MEST/KOSEF
文摘The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a friction force at the contact surface between the tube and the tool occurs. In guiding zone, the friction coefficients between tube and die can be estimated from the measured axial feeding forces. In expansion zone, the friction coefficients between tube and die can be evaluated from the measured geometries of expanded tubes and FE analysis.
