Showing papers by "Taylan Altan published in 2009"
TL;DR: In this paper, the performance of stamping lubricants was evaluated by using the deep drawing and ironing tests, and the results showed that polymer-based thin film lubricants with pressure additives were more effective than other lubricants as shown by the force and geometry indicators.
87 citations
TL;DR: In this paper, experiments with varying cutting conditions and tool edge geometry were performed concurrently with finite element simulations to investigate how the two mechanisms reported in literature namely, surface shear-cracking (SCH) and catastrophic thermoplastic instability (CTI) contribute to overall chip geometry and machining forces.
68 citations
TL;DR: In this paper, the effects of edge radius of a round-edge coated carbide tool on chip formation, cutting forces, and tool stresses in orthogonal cutting of an alloy steel 42CrMo4 (AISI 4142H) were investigated.
Abstract: This paper investigates the effects of edge radius of a round-edge coated carbide tool on chip formation, cutting forces, and tool stresses in orthogonal cutting of an alloy steel 42CrMo4 (AISI 4142H). A comprehensive experimental study by end turning of thin-walled tubes is conducted, using advanced coated tools with well-defined cutting edge radii ranging from 5 to 68 microns. In parallel, 2-D finite element cutting simulations based on Lagrangian thermo-viscoplastic formulation are used to predict the cutting temperatures and tool-stress distributions within the tool coating and substrate. The results obtained from this study provide a fundamental understanding of the cutting mechanics for the coated carbide tool used, and can assist in the optimization of tool edge design for more complex geometries, such as chamfered edge. Specifically, the results obtained from the experiments and simulations of this study demonstrated that finite element analysis can significantly help in optimizing the design of c...
39 citations
01 Jan 2009
TL;DR: In this article, the elastic and plastic properties of AHSS were determined by using the tensile test and the biaxial bulge test, and the springback for bending and flanging advanced high-strength steel (AHSS) was investigated by using experimental methods and computation models.
Abstract: In this study, springback for bending and flanging advanced high-strength steel (AHSS) was investigated by using experimental methods and computation models. The elastic and plastic properties of AHSS were determined by using the tensile test and the biaxial bulge test. Dual-phase (DP) 600 showed significant decreases about 10% of unloading elastic modulus as the effective strain increased during loading and unloading cyclic tensile tests, while aluminum-killed drawing quality (AKDQ) gave almost constant modulus. Therefore, a general expectation of constant elastic modulus of material will not always apply to AHSS. The V-bend test was used to investigate the effects of material properties, texture orientations, and die openings on springback. The experimenatal results showed that TRIP 780 has relatively smaller springback compared to DP 780 and 780 HY (high yield) materials at two different die opening lengths. Experimental results were compared to the predictions of computation model. Preliminary tests with an S-rail flanging die were conducted with AKDQ material to investigate the feasibility of this test method for springback study. In addition, finite-element (FE) simulations for S-rail flanging of AKDQ and DP 780 were conducted to predict the thinning distribution. Springback simulations were conducted for DP980 S-rail part with constant and variable elastic modulus. The variable elastic modulus gave the higher magnitude of springback compared to the constant elastic modulus model.
6 citations