Stamping

About: Stamping is a research topic. Over the lifetime, 22501 publications have been published within this topic receiving 83554 citations.

The effect of process temperature on the formability of polypropylene based fibre-metal laminates

Abstract: In developing a methodology for a robust stamp-forming process for glass–fibre reinforced thermoplastic Fibre–Metal Laminate (FML) systems, an understanding of the effects of process variables on critical formability measures is required. This study recognises temperature as the primary process condition and investigates the thermal profile of an FML for a range of potential processes. These profiles have been applied to the stamping of a channel section and their success quantified using shape error, bend radius and delamination measures. It was found that it is necessary to pre-heat the laminate to 160 °C followed by rapid transfer to the press tooling which should be heated to 80 °C. Once formed, the part should be held between the die and punch until the polymer has solidified. Significant improvements in shape error were achieved compared to monolithic aluminium formed with the same process. This indicates that in addition to providing significant weight savings, FML systems have potential for superior formability characteristics compared to monolithic aluminium material systems for large volume production of components using stamp forming.

Effect of microstructure and texture on forming behaviour of AA-6061 aluminium alloy sheet

Abstract: AA-6061 aluminium alloys are used extensively in automobile and aerospace industries owing to their excellent combination of mechanical and physical properties. This alloy exhibits prominent anisotropy in mechanical properties when produced as cold rolled sheets. In manufacturing, sheet metal anisotropy may have severe consequences for downstream processes such as stamping and deep drawing operations. In the present study, correlations among in-plane anisotropy, strain path and formability of AA-6061 sheet metal are investigated. Using limit dome height tests, forming limit diagrams (FLDs) were constructed for three different sheet directions by applying appropriate strain localization and fracture criteria. For each sheet direction and strain path, microstructure and texture evolution were also observed to identify the origin of in-plane anisotropy and formability of the AA-6061 sheet metal alloy. A detailed analysis of microstructure under different strain paths suggests the direction and texture dependent yield locus to be a significant factor for in-plane anisotropy. Intra-granular crack propagation in a particular sheet direction (transverse direction: TD) may lead to reduced formability of AA-6061. Formability, on the other hand, appears to be highly correlated to the relative fraction of specific texture components. Certain critical texture components such as Cube {001} and Brass {011} influence the forming behaviour of AA-6061 aluminium alloy significantly.

Influence of process parameters on the thermostamping of a [0/90]12 carbon/polyether ether ketone laminate

Abstract: In this study, an experimental evaluation of the thermostamping process was made for a 3D part molded with a [0/90] 12 laminate composed of unidirectional carbon fiber/polyether ether ketone (CF/PEEK) plies. Using the Taguchi method, the effect of four operational parameters on the part thickness, interlaminar shear strength and the degree of crystallinity were investigated. These parameters are the preheating temperature in the oven, the mold temperature, the oven to mold transfer time and the stamping pressure. The results show that the mold temperature and stamping pressure have a significant effect on part consolidation. In addition, the interlaminar shear strength, measured at the base of the molded part, was higher for thinner parts compared to those having a greater thickness. These results were also confirmed by Differential Scanning Calorimetry analysis, which show that the degree of crystallinity is higher for thinner parts.