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Bending in sheet metal forming is defined as uniformly straining process around a linear axis. A V-bending process is normally used in sheet metal working due to the tool and process simplicity. The main problem in bending process is a springback occurrence which causes an error in part dimension. In a micro level, the springback angle is difficult to be assessed because of the influence of size effects in all aspects of the system. The springback behavior has been investigated in many previous kinds of research. However, the springback correction is still needed to be studied extensively so that it can be implemented reliably in micro-bending. The purpose of this research is to investigate the influence of punch velocity and holding time to the springback angle. The process is performed to the 0.1 mm thickness of copper foil. The punch velocities are 0.1 mm/s, 1 mm/s, and 10 mm/s. While the variation of holding time, which is set during the bottoming stage, are 7 s, 9 s, and 11 s. The result shows that the punch velocity clearly influences the springback angle. In addition, the holding time during the bottoming stage is a potential factor in springback angle correction.

Superplastic forming (SPF) is a material forming technique that uses superplastic exceptional elongations and deformation characteristics to form superplastic materials into certain shapes. The combination of superplastic forming with diffusion bonding (SPF/DB) gives rise to an almost unlimited extension of superplastic forming since more integral lightweight cellular structural components can be manufactured. This paper discusses numerical modelling of the mechanism of superplasticity in metallic materials. The SPF computational method based on the finite element technique augmented with the controlling rate of deformations is developed to examine a range of design or operating conditions leading to more economical forming processes. The non-Newtonian 'viscous flow' material is used to model the constitutive of superplastic material during the forming period. The contact mechanics between the sheet material and the mold surface and the intersheet material contact mechanics are imposed using the penalty control method, in which the sticking contact boundary conditions are employed. The space discretization is carried out using the membrane element under plane strain and axisymmetric flow stress conditions, while the implicit time integration technique is utilized to follow the shape changes of the formed sheet material. The validation of the SPF finite element formulation was performed by comparing it with the available analytical solution of Hydraulic Free Bulging of Thin strips. The SPF of a hemispherical dome made of 7475 aluminum sheet alloy was performed to demonstrate the forming process as well as to validate the results obtained between the SPF finite element numerical simulation and the experimental results. The SPF/DB of the multicell component section is considered in the final part. [ABSTRACT FROM AUTHOR]

A Pulsed Laser Deposition (PLD) technique is a type of physical vapor deposition (PVD) technology. This research is one of a series of PVD studies aimed at determining the best PLD coating that can minimize the damage of steel pins made of SKD61 with a hardness of 48±1 HRc. The study began with the dummy blocks from SKD61 as research samples, followed by PVD-PLD with three coating materials as alternatives: Al/Cr (70:30), Al/Ti1 (50:50), and Al/Ti2 (63:37), all without active gases (N and C). The procedures used to test the research findings were FESEM, SEM, XRF, EDS, Vickers, and Rockwell Microhardness. The experiments were conducted at the BRIN Fotonic Research Center and the PT AHM Laboratory. The PLD process lasted for 10 minutes and employed an Nd: YAG laser with a wavelength of 1064 nm, a Q-switch with a time delay of 180 s, a pulse energy of 70 mJ, and a vacuum pressure of 1.161.35 Torr. Based on the results of the coating study, an AlTi1 coating was found to be the most effective material coating. The coating consisted of amorphous particles with a size range of 10 nm to 20 nm The coating had a thickness of 23 µm, and the surface hardness was measured to be 474-523 mHv for the single-layer coating and 477-501 mHv for the multilayer coating. The materials in both single-layer and multilayer coating samples have the same hardness in ascending order: AlCr, AlTi2, AlTi1, with a Ti concentration rise from 0.7% to 3.7%. The impact of the Ti element is also crucial in increasing hardness, wear resistance, and roughness. [ABSTRACT FROM AUTHOR]