CAJ | 학술논문

研究纯钛板材冷拉成形过程中微观组织及织构演化规律.半球形壳体件在深拉延过程中由于各部位变形模式及应变形式的不同会形成胀形区、拉深区及法兰区等3个区域.结果表明,在拉深件的3个区域中塑性应变均由位错滑移与变形孪晶共同作用.纯钛板材及其拉深件中的织构包含轧制织构与再结晶织构.由于变形孪晶与位错滑移对织构的影响规律不同,初始板材织构的强度及类型在深拉过程中不断变化.变形孪晶对初始织构具有弱化作用,特别是对于再结晶织构,这种弱化效应更为明显.由于拉深区产生的孪晶较多,再结晶织构消失.此外,大拉伸变形时位错滑移为主导机制,织构强化效应明显.
연구순태판재랭랍성형과정중미관조직급직구연화규률.반구형각체건재심랍연과정중유우각부위변형모식급응변형식적불동회형성창형구、랍심구급법란구등3개구역.결과표명,재랍심건적3개구역중소성응변균유위착활이여변형련정공동작용.순태판재급기랍심건중적직구포함알제직구여재결정직구.유우변형련정여위착활이대직구적영향규률불동,초시판재직구적강도급류형재심랍과정중불단변화.변형련정대초시직구구유약화작용,특별시대우재결정직구,저충약화효응경위명현.유우랍심구산생적련정교다,재결정직구소실.차외,대랍신변형시위착활이위주도궤제,직구강화효응명현.
The development of microstructure and texture during cold deep drawing of commercially pure titanium (CP-Ti) was investigated.Three parts,stretching region,drawing region and flange region,were sequentially formed in the deep drawing process of the hemispheric surface part,with reference to deformation modes and strain regimes.Results show that the plastic strain is accommodated by dislocation slip and deformation twinning in the whole deep drawing process.The texture of the CP-Ti sheet and its drawn part consists of rolling texture component and recrystallization texture component.The intensity and type of the initial texture varied during the drawing process are related to the production of deformation twinning and dislocation slip.Twinning weakens the initial texture by randomizing the orientations of crystals,especially for the recrystallization texture.The recrystallization texture in the drawing region disappears due to the significant forming of twinning.Furthermore,over drawing would result in the predominance of dislocation slip and the texture is strengthened.