Deep drawing parts of multilayer sheet metals are widely used in the aerospace, automobile and chemical industries due to its excellent comprehensive mechanical properties. In recent years, many researches have been done regards the deep drawability and wrinkle behavior of multi-layer sheets. When investigate the deep drawability of multi-layer sheets, the influence of basic deep drawing process parameters, stacking sequence and thickness ratio of component metals on the deep drawability of multilayer sheet is emphatically studied while the influence of interfacial friction is rarely discussed. The constantly changed space position and surface shape of unsupported area of formed sheet parts during the deep drawing process combined with the difference in mechanical properties between component metals make the wrinkling mechanism of multi-layer sheets more complicated to investigate. Thus, at present, the research on wrinkling of multi-layer deep drawing parts is mainly focused on the external 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 the punch side, increasing the thickness ratio of component metal with better formability and optimizing the basic deep drawing parameters, the deep drawability of multi-layer sheets can be improved. Meanwhile, relevant studies on the wrinkling mechanism gives that: the strength of component metal and the interaction between component metal during deformation are the main reasons for wrinkling of multi-layer sheets deep drawing. For 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: deep drawability and wrinkling. Based on this, double-layer sheets hydroforming was proposed and the wrinkle defects of thinner curved sheet parts can be eliminated by controlling of relevant process parameters reasonably. The exist problem of recent research in this area is summarized and future research direction is prospected, finally. © 2020, Materials Review Magazine. All right reserved.
