Advanced Forming Technology for Lightweight Components: From Theory to Application

The use of lightweight component is inevitable issue for the protection of global environment. Transportation vehicle with the lightweight component can reduce the emission gas and increase fuel efficiency. First of all, the advanced forming technology is extremely important to fabricate the lightweight component. Knowledge and understanding of this advanced forming technology can lead to the development of the ultralightweight vehicle and, furthermore, can play an important role in fostering the ecofriendly global world.

The main objective of this special issue is to collect original research articles as well as review articles that stimulate the continuing efforts to understand the theoretical methodology and the numerical analysis on the advanced forming process and its actual experiment and application, a new insight into the formation of the lightweight component, advanced numerical simulation approach, and state-of-the-art technology in the formation of lightweight component using ultrahigh strength steel, aluminum alloy, magnesium alloy, composites, and so forth.

In this special issue, the editors received 30 manuscripts on various topics of advanced forming technology. After peer review and based on the comments from reviewers, 17 manuscripts have been rejected and 13 manuscripts have been accepted. A brief overview of the manuscripts is as follows.

In the paper titled “Feasibility study on flexibly reconfigurable roll forming process for sheet metal and its implementation,” J.-S. Yoon et al. proposed a new sheet metal forming process called the flexibly reconfigurable roll forming (FRRF) process as an alternative to existing processes for producing a multicurved sheet metal surface for a skin structure, where adjustable punches and upper and lower reconfigurable rollers as forming tools were used. In the paper titled “Research on integrated casting and forging process of aluminum automobile wheel,” Q. Zhang et al. produced aluminum structure parts, such as aluminum alloy automobile wheel, with complex shape and excellent mechanical properties by using integrated casting and forging process (ICFP) which is a new manufacturing method combining the advantages of both casting and forging. In the paper titled “A study on process design of automobile parts using extruded material by die forming,” D. Kim et al. designed die forming processes with precision dies to manufacture automobile control arm and subframe parts using aluminum extruded. In the paper titled “Research on continuous injection direct rolling process for PMMA optical plate,” H. Wang et al. proposed continuous injection direct rolling (CIDR) combined with intermittent injection and rolling process as a new technology to mold optical polymer plates with microstructured patterns. Based on establishing mathematical CIDR models, numerical analysis was performed to explode the distribution of velocity, temperature, and pressure in injection-rolling zone. In the paper titled “Cooling systems design in hot stamping tools by a thermal-fluid-mechanical coupled approach,” a new multifield simulation method was proposed for the design of hot stamping tools with cooling system by T. Lin et al. based on MpCCI (mesh-based parallel code coupling interface); thermal-fluid simulation and thermal-fluid-mechanical coupled simulation were performed and then the geometrical parameters of the cooling system were investigated for the design. In the paper titled “The effect of process and model parameters in temperature prediction for hot stamping of boron steel,” C. Sun et al. developed finite element models of the hot stamping and cold die quenching process for boron steel sheet, where the effect of tool elasticity and process parameters on work-piece temperature was investigated. In the paper titled “Effect of the die temperature and blank thickness on the formability of a laser-welded blank of a boron steel sheet with removing Al-Si coating layer,” the formability of a laser-welded boron steel sheet to improve crash energy absorption capacity in hot stamped parts was investigated by M. S. Lee et al., where a certain part of Al-Si coating layer was removed by laser ablation to avoid weakening at the welding spot. In the paper titled “Comparative numerical analysis of sheet formed into a V-shaped die using conventional and electromagnetic forming processes,” J. Kim et al. showed that damage suppression due to the tool-sheet interaction was one of the main factors contributing to the increased formability in the electromagnetic forming (EMF) as compared to the conventional forming operation and, additionally, a high level of kinetic energy produced high strain-rate constitutive and inertial, which delayed the onset of necking and increased the formability. In the paper titled “LBW/SPF/DB combined processing and microstructure of TA15 titanium alloy four-layer sandwich structure with square grid,” J. Shaosong et al. produced TA15 titanium alloy sandwich structure with square grid using the process combined laser beam welding, superplastic forming, and diffusion bonding (LBW/SPF/DB) and analyzed the microstructure of different regions before and after superplastic forming. In the paper titled “A research on the creep age forming of 2524 aluminum alloy: springback, mechanical properties, and microstructures,” L. Zhan et al. performed a series of orthogonal tests to investigate the combined effects of aging temperature, time, predeformation, and part thickness features on the springback of creep age formed of 2524 aluminum alloy sheets. In the paper titled “Fabrication of gear having functionally graded properties by direct laser melting process,” S.-W. Han et al. demonstrated the possibility to produce functionally graded properties in gear through the direct laser melting of compositionally selected metallic powders, where properties of manufactured parts depended strongly on each single laser-melted track. In the paper titled “Differential speed rolling to reduce warping in bimetallic slab,” C. H. Lee et al. investigated the effect of differential speed rolling on the reduction of warping by using FEM based on fundamental processing parameters. In the paper titled “Prediction of bending stiffness for laminated CFRP and its application to manufacturing of roof reinforcement,” J.-M. Lee et al. evaluated the effect of the stacking sequence on the bending stiffness and validated it through experiments under the same conditions as the analysis.

Dae-Cheol Ko Jianguo Lin Jun Yanagimoto Woo-Jin Song