The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Taylan Altan - One of the best experts on this subject based on the ideXlab platform.

  • tool life in cold forging an example of design improvement to increase service life
    Journal of Materials Processing Technology, 2000
    Co-Authors: Victor Vazquez, Daniel Hannan, Taylan Altan
    Abstract:

    Abstract The production cost for cold forgings depends significantly on the tool life. This paper summarizes an investigation of different alternatives to improve the life of a tungsten carbide insert used in a cold Forming Operation performed on an automatic cold header. These alternatives were as follows: (a) double tapered insert, (b) split insert design, and (c) change of insert material. Although, the techniques were applied to a specific case, they might he applicable to other cold forging tooling. To improve the life of the insert, the metal flow and stress analysis of the carbide insert was conducted using the commercial FEM software DEFORM .

  • improvement of tool life in cold forging of complex automotive parts
    Journal of Materials Processing Technology, 1994
    Co-Authors: Yuichi Nagao, Markus Knoerr, Taylan Altan
    Abstract:

    Abstract In cold forging of outer races for constant velocity joints tool loads during the backward extrusion Operation lead to very high loading conditions in the tool inserts. Fatigue cracking is the common failure mode that ends the service life of the tooling. This paper analyzes the stress states that exist in the inserts during the Forming Operation and determines the causes of the fatigue failures. Advanced tooling design concepts using a profiled, strip-wound stress container are investigated in order to change the loading conditions in the dies in a way that crack initiation can be avoided. The design concept is verified by a specially designed laboratory forging test. The test results show that the stress state in a die can be reduced with the new tooling concept and that the fatigue failure can be avoided.

Michael R. Lovell - One of the best experts on this subject based on the ideXlab platform.

  • Development of a Novel Green Lubricant for Sheet Metal Forming Operation
    ASME STLE 2007 International Joint Tribology Conference Parts A and B, 2007
    Co-Authors: M A Kabir, Michael R. Lovell
    Abstract:

    The main purpose of the present investigation is to analyze a novel, green, and petroleum-free lubricant that is produced by mixing two environmentally benign components—canola oil and boric acid powder. To study the influence of boric acid crystal size and volume ratio on the proposed lubricants performance, computerized pin on disk experiments were conducted with spherical copper pins (radius 6.5 mm) and aluminum disks (Ra = 1.35μm). Friction coefficient measurements were taken at more than twenty distinct operating conditions while varying the lubrication condition (unlubricated, boric acid, canola oil, boric acid/canola oil mixture), boric acid volume fraction (3.5%, 7%, 10.5 and 21%), and boric acid crystal size (0–100 microns, 100–150 microns, 150–180 microns, 180–350 microns and 350–710 microns). Based on the experiments, it was determined that a 7% by volume boric acid powder in canola oil with 350–700 micron particles was the optimum green lubricant for minimizing the friction at the conditions tested. In addition, the results indicated that the boric acid/canola oil lubricant demonstrated excellent potential for use in industrial applications such as sheet metal stamping.Copyright © 2007 by ASME

  • predicting springback in sheet metal Forming an explicit to implicit sequential solution procedure
    Finite Elements in Analysis and Design, 1999
    Co-Authors: Narkeeran Narasimhan, Michael R. Lovell
    Abstract:

    The springback properties of sheet metals make the design of Forming dies extremely difficult. In this work a coupled explicit to implicit finite element procedure is outlined for predicting springback deformations in sheet metal Forming processes. The explicit method is initially utilized to analyze the contact based Forming Operation of a production stamping process. Then, an implicit solution is performed to simulate the springback that develops in a blank after the Forming pressure has been removed. Using this simultaneous solution technique on an actual automotive component, numerically predicted springback deformations are found to be within 1% of production values. The results of the numerical investigation indicate that the coupled finite element procedure described herein can be utilized to significantly reduce the number of die prototype designs that are currently required in sheet metal stamping Operations.

Edmund Chu - One of the best experts on this subject based on the ideXlab platform.

  • Theoretical prediction of the springback of metal sheets after a double-curvature Forming Operation
    Journal of Materials Processing Technology, 1999
    Co-Authors: P. Xue, Edmund Chu
    Abstract:

    Abstract By establishing a mechanics model and corresponding analytical procedure based on the membrane theory of shells of revolution and an energy method, a theoretical prediction of springback is formulated for thin metal sheets after they have undergone a double-curvature Forming Operation, e.g. stamping and stretching-bending. The strain-hardening of the material is incorporated into the mechanics model. The effect of stretching force applied at the edge of the plates on springback is also considered. Excellent agreement is found between the theoretical prediction of springback and experiment results. It is shown that the procedure developed is capable of quantitatively predicting the springback of circular and square plates after axisymmetric stamping with a relatively minor effort of calculation and a good accuracy.

  • Theoretical prediction of the springback of metal sheets after a double-curvature Forming Operation
    Journal of Materials Processing Technology, 1999
    Co-Authors: P. Xue, Edmund Chu
    Abstract:

    By establishing a mechanics model and corresponding analytical procedure based on the membrane theory of shells of revolution and an energy method, a theoretical prediction of springback is formulated for thin metal sheets after they have undergone a double-curvature Forming Operation, e.g. stamping and stretching-bending. The strain-hardening of the material is incorporated into the mechanics model. The effect of stretching force applied at the edge of the plates on springback is also considered. Excellent agreement is found between the theoretical prediction of springback and experiment results. It is shown that the procedure developed is capable of quantitatively predicting the springback of circular and square plates after axisymmetric stamping with a relatively minor effort of calculation and a good accuracy. (C) 1999 Elsevier Science S.A. All rights reserved

Arunansu Haldar - One of the best experts on this subject based on the ideXlab platform.

  • design and development of precipitate strengthened advanced high strength steel for automotive application
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013
    Co-Authors: Subhasis Sinha, Arijit Lodh, Arunansu Haldar
    Abstract:

    Abstract Stringent safety and pollution control norms forces the car industry to use higher strength steels in different components of an automobile. However, high strength steels typically possess less formability which makes Forming Operations difficult. Thus developing high strength steel, with better formability for automotive application, is a challenge for all the steel companies those are working to solve in different ways. In the present work, a new approach, from designing of steel composition to finalizing the process parameters, to develop high strength steel (minimum 1000 MPa UTS) with high elongation (minimum 15%) will be discussed in details. High elongation of this steel is expected to make the Forming Operation easier without compromising with the strength.

Jae-chan Choi - One of the best experts on this subject based on the ideXlab platform.

  • The influence of induction heating on the microstructure of A356 for semi-solid forging
    Journal of Materials Processing Technology, 1999
    Co-Authors: Jae-chan Choi
    Abstract:

    Abstract Semi-solid forging is a compound forging technology to develop conventional forging process. Among the several steps of the semi-solid forging process, the heating step of the billet prior to semi-solid forging step is necessarily required to obtain a globular microstructure. For the Forming Operation to work properly, it is important to heat the billet uniformly for the uniformity of solid–liquid distribution and globular grain. It is also required to heat the billet as soon as possible. To satisfy these requirements, induction heating has been generally used for a long time. This paper presents a method to find the heating condition and the temperature distribution inside the billet with induction heating apparatus by comparing computer simulation with experiment for A356. The microstructure of the billet is also investigated by using a conventional parameter, i.e. the mean size of globules, in connection with the heating condition.