Investigation on Contact Heating of Aluminum Alloy Sheets in Hot Stamping Process

Abstract

Application of the hot stamping process on heat-treatable aluminum alloys effectively solves the problems of large springback and poor ductility during forming at room temperature, which expands the range of applications of aluminum alloys in the transportation industry. Sheet heating plays an important role in the hot stamping process, and increasing the heating rate can improve the hot stamping efficiency to some extent. In this paper, the feasibility of applying contact heating techniques with higher heating rates in the hot stamping process was studied. A contact heating device was designed, and the temperature distribution of the device contact surface was observed. Furthermore, the heating characteristics of 7075 aluminum alloy sheets during the contact heating process were explored by experiments and finite element simulation. Finally, the rapid solution treatment of aluminum alloy was carried out with a contact heating device, which was compared with the furnace heating solution treatment. The experimental and simulation results indicate that the device contact surface has a relatively uniform temperature distribution, and the aluminum alloy sheets can be heated to close to the set temperature in 15 s using contact heating techniques. Meanwhile, the rapid solution treatment of aluminum alloy sheets can be achieved within 15–20 s by contact heating techniques, obtaining superior mechanical properties. This suggests that the contact heating process can be used for rapid heating and rapid solution treatment of aluminum alloy sheets in hot stamping process.

Investigation on effect of high-efficiency solid solution and hot stamping process on microstructure evolution and mechanical properties of high-strength aluminum alloy

“…However, they also found that the temperature uniformity was inadequate, and proposed that the configuration of the flame nozzles be arranged reasonably to enhance the temperature distribution across the sheet. Our research indicates that using the contact heating process on a 7075 sheet with a thickness of 2 mm, can achieve solid solution temperature (480 o C) within 15 to 20 seconds [7].…”

Thermal Expansion of Plastics Used for 3D Printing

“…It was developed a steady-state thermal FEM analysis considering the convection phenomena. Approximate convection coefficient values for aluminum alloys were confronted with those presented by Geng et al [ 23 ]. It has conducted the analyses on ABS simulating the heat transfer for the cool environment, which starts from around −10 ° C and records about 13 °C on the top side of the cover plate ( Table 2 ).…”

Low-Carbon-Emission Hot Stamping: A Review from the Perspectives of Steel Grade, Heating Process, and Part Design

“…18. The result showed that the heating rate reached 28.7 °C/s and the heating time to a solution treatment temperature of aluminum alloy could be reduced from around 8 min to 15-20 s in comparison with furnace heating [64]. Contact heating is also one good solution for partial heating by controlling the contact surface.…”

“…17 Sequence of bending processes with local infrared heating [63] Fig. 18 The schematic of a device and b contact heating [64] Fig. 19 Cylindrical deep drawing by partial contact heating and whole furnace heating [65] cooling rates could be one of the significant challenges for its application.…”