【摘要】 多层板拉深件由于具备优异的综合力学性能,在航空航天、汽车以及化工等领域得到了广泛的应用,近年来围绕多层板的拉深成形性能及起皱行为开展了较多的研究工作。在拉深成形性能方面重点研究了基本拉深成形工艺参数、组元金属的叠层顺序、厚度比等对多层板拉深成形性能的影响,对界面摩擦的影响则鲜有涉及。由于不同组分金属力学性能的差异,加之发生内皱(多指悬空区起皱)区域的材料在拉深成形过程中的空间位置及曲面形状均在不断发生变化,加大了多层板拉深成形起皱机理及控制的研究难度,目前在多层板拉深成形起皱方面主要还是针对外皱展开研究,对复杂曲面零件悬空区起皱机理的研究则相对较少。针对多层板拉深成形性能影响因素的研究表明,将成形性能更好的组元金属置于凸模一侧、增加多层板中成形性能更好的组元金属的厚度比、优化基本的拉深成形工艺参数均能提高多层板的拉深成形性能。针对其起皱机理的相关研究表明,组元金属的强度、变形过程中组元金属之间是否存在相互作用(厚向约束以及变形协调)等是多层板拉深成形发生失稳起皱的主要原因。研究结果为多层板的结构设计以及实际应用提供了理论指导。本文从拉深成形性能和起皱两个方面综述了近年来国内外在多层板拉深成形方面的研究现状及主要存在的问题,在此基础上提出了双层板充液拉深成形方法,通过对相关工艺参数的合理调控,可以消除薄壁曲面件悬空区起皱缺陷,获得合格试件。最后在总结现有研究存在的问题的基础上对多层板拉深成形的未来研究方向进行了展望。更多还原

【Abstract】 Deep drawing parts of multilayer sheet metals are widely used in the aerospace,automobile and chemical industries due to its excellent com prehensive mechanical properties. In recent years,many researches have been done regards the deep drawability and wrinkle behavior o multi-layer sheets.When investigate the deep drawability of multi-layer sheets,the influence of basic deep drawing process parameters,stacking sequence an thickness ratio of component metals on the deep drawability of multilayer sheet is emphatically studied while the influence of interfacial friction i rarely discussed. The constantly changed space position and surface shape of unsupported area of formed sheet parts during the deep drawin process combined with the difference in mechanical properties between component metals make the wrinkling mechanism of multi-layer sheet more complicated to investigate. Thus,at present,the research on wrinkling of multi-layer deep drawing parts is mainly focused on the externa wrinkle defects,while relatively few researches focus on the wrinkling mechanism of unsupported area for complex curved sheet parts.Research on the influence factor of deep drawability of multilayer sheets shows that by placing the component metal with better formability in th punch side,increasing the thickness ratio of component metal with better formability and optimizing the basic deep drawing parameters,the dee drawability of multi-layer sheets can be improved. Meanwhile,relevant studies on the wrinkling mechanism gives that: the strength of componen metal and the interaction between component metal during deformation are the main reasons for wrinkling of multi-layer sheets deep drawing. Fo the structural design and practical application of multilayer sheet metals,the above research findings have certain theoretical guidance meaning An overall review of research status and existing problems for deep drawing of multilayer sheet metals is summarized from two aspects: dee drawability and wrinkling. Based on this,double-layer sheets hydroforming was proposed and the wrinkle defects of thinner curved sheet parts ca be eliminated by controlling of relevant process parameters reasonably. The exist problem of recent research in this area is summarized and futur research direction is prospected,finally.更多还原