Energy-input-based finite-element process modeling of inertia welding
- PDF / 895,099 Bytes
- 11 Pages / 612 x 792 pts (letter) Page_size
- 50 Downloads / 239 Views
I. INTRODUCTION
INERTIA welding is a solid-state process for joining similar and dissimilar[1,2,3] work-pieces with axially symmetric joint surfaces. As such, it has been examined for the joining of high containing Ni superalloy aeroengine discs[4,5,6] and oxide-dispersion-strengthened materials[7] that would be very difficult using conventional fusion welding techniques. During inertia friction welding, one of two workpieces is connected to a flywheel and the other is restrained from rotating. The flywheel is accelerated to a predetermined rotational speed and then disengaged from the drive, and the work-pieces are forced into contact by applying axial pressure.[2] During the welding process, the initial rotational kinetic energy from the flywheel is mostly transferred to the welding components as redundant frictional/plastic heat raising the temperature and softening the material. A small proportion of the heat dissipates through the local plastic deformation experienced by the work-pieces, which are essentially forged together. In the immediate vicinity of the joint, the thermal excursion is severe and the heating and cooling rates are very high. Consequently, the microstructure varies sharply in the vicinity of the joint.[5] This has a significant impact on the local mechanical properties in this region. To date, only a small number of numerical models of the inertia friction welding process have been reported in the literature. Davé et al.[8] developed an analytical model of the heat generation in inertia welding of dissimilar tubes. Although the model employs major simplifications such as temperature-averaged materials properties, the article asserts that the simple model provides good guidance in weld parameter development for dissimilar inertia welding. Balasubramanian[9,10] undertook a solely thermal analysis for the simulation of inertia welding dissimilar materials in order L. WANG, Senior Engineer, is now with Wilde FEA, United Kingdom. M. PREUSS, Lecturer in Materials Performance, and P.J. WITHERS, Professor in Materials, are with the School of Materials, The University of Manchester, Manchester, M1 7HS, United Kingdom. Contact e-mail: [email protected] G. BAXTER, Process Metallurgist, and P. WILSON, Technical Coordinator, are with Rolls-Royce Plc., Derby, DE24 8BJ, United Kingdom. Manuscript submitted November 4, 2003. METALLURGICAL AND MATERIALS TRANSACTIONS B
to obtain the temperature distribution, where the coupling between deformation and temperature was not considered. D’Alvise[11] performed a coupled thermal and mechanical analysis to predict the temperature, residual stress, and strain field for dissimilar welds. However, the model was only validated in terms of the macroprocess variables such as welding time, total loss of length, and flash profile. Temperature histories were recorded during the associated welding trials using thermocouples. Due to the loss of length of the component during friction welding, the thermocouples had to be placed well away from the original weld
Data Loading...
