Taylan Altan

Bio: Taylan Altan is an academic researcher from Ohio State University. The author has contributed to research in topics: Forging & Finite element method. The author has an hindex of 59, co-authored 270 publications receiving 14494 citations. Previous affiliations of Taylan Altan include University College of Engineering & DuPont.

Investigation of the Effect of Tool Edge Geometry upon Cutting Variables, Tool Wear and Burr Formation Using Finite Element Simulation — A Progress Report

Abstract: This paper summarizes some of the progress made on FEM simulations of metal cutting processes conducted at the Engineering Research Center (ERC/NSM). Presented research focuses on the performance of various cutting edge geometries (hone and chamfer edges) for different tool materials and specifically on: 1) the effect of round and chamfer edge geometries on the cutting variables in machining carbon steels and 2) the effect of the edge hone size upon the flank wear and burr formation behavior in face milling of A356‐T6 aluminum alloy. In the second task, an innovative design of edge preparation with varying hone size around the tool nose is also explored using FEM.In order to model three‐dimensional conventional turning and face milling with two‐dimensional orthogonal cutting simulations, 2D simulation cross‐sections consisting of the cutting speed direction and chip flow direction are selected at different locations along the tool nose radius. Then the geometries of the hone and chamfer edges and their as...

Double Cup Extrusion Test to Evalute Lubricants for Cold Forging

Abstract: The double cup extrusion test was developed and used extensively for evaluating lubricants in cold forging. This test emulates the high material/tool interface pressures and large surface expansion that occur in industrial cold forging operations. This short paper summarizes the principles of this test and illustrates how it is used to evaluate environmentally friendly lubricants.

Forming Al and Mg Alloy Sheet and Tube at Elevated Temperatures

Abstract: Experimental investigation on the formability limits of aluminum and magnesium alloys are conducted through hydraulic bulging and deep drawing. New tube hydroforming tooling was designed and the submerged tool concept is introduced. Tube hydroforming experiments were conducted with and without axial feed by using AA6061 tubes. The formability of Mg AZ31-O sheets are determined by hydraulic bulging using similar submerged tool. Finally the effect of temperature and initial blank size on the attainable highest punch velocity is investigated and round cups from Mg AZ31-O were successfully formed in a heated tool with punch speeds up to 300 mm/s.

State of the art electrical discharge machining (EDM)

Abstract: Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests. In recent years, EDM researchers have explored a number of ways to improve the sparking efficiency including some unique experimental concepts that depart from the EDM traditional sparking phenomenon. Despite a range of different approaches, this new research shares the same objectives of achieving more efficient metal removal coupled with a reduction in tool wear and improved surface quality. This paper reviews the research work carried out from the inception to the development of die-sinking EDM within the past decade. It reports on the EDM research relating to improving performance measures, optimising the process variables, monitoring and control the sparking process, simplifying the electrode design and manufacture. A range of EDM applications are highlighted together with the development of hybrid machining processes. The final part of the paper discusses these developments and outlines the trends for future EDM research.

Metal Forming and the Finite-Element Method

Abstract: Introduction Metal forming process Analysis and technology in metal forming Plasticity and viscoplasticity Methods of analysis The finite element method (1) The finite element method (2) Plane-strain problems Axisymmetric isothermal forging Steady state processes of extrusion and drawing Sheet metal forming Thermo-viscoplastic analysis Compaction and forging of porous metals Three dimensional problems Preform design in metal forming Solid formulation, comparison of two formulations, and concluding remarks Index.

The yield stress—a review or ‘παντα ρει’—everything flows?

Abstract: An account is given of the development of the idea of a yield stress for solids, soft solids and structured liquids from the beginning of this century to the present time. Originally, it was accepted that the yield stress of a solid was essentially the point at which, when the applied stress was increased, the deforming solid first began to show liquid-like behaviour, i.e. continual deformation. In the same way, the yield stress of a structured liquid was originally seen as the point at which, when decreasing the applied stress, solid-like behaviour was first noticed, i.e. no continual deformation. However as time went on, and experimental capabilities increased, it became clear, first for solids and lately for soft solids and structured liquids, that although there is usually a small range of stress over which the mechanical properties change dramatically (an apparent yield stress), these materials nevertheless show slow but continual steady deformation when stressed for a long time below this level, having shown an initial linear elastic response to the applied stress. At the lowest stresses, this creep behaviour for solids, soft solids and structured liquids can be described by a Newtonian-plateau viscosity. As the stress is increased the flow behaviour usually changes into a power-law dependence of steady-state shear rate on shear stress. For structured liquids and soft solids, this behaviour generally gives way to Newtonian behaviour at the highest stresses. For structured liquids this transition from very high (creep) viscosity (>106 Pa.s) to mobile liquid (