| Author: | Zhang, Yin |
| Title: | Simulation-enabled prediction of metal-formed product defect and defect avoidance |
| Degree: | M.Sc. |
| Year: | 2013 |
| Subject: | Metal-work -- Simulation methods. Metal-work -- Quality control. Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Mechanical Engineering |
| Pages: | ix, 123 leaves : ill. (chiefly col.) ; 30 cm. |
| Language: | English |
| Abstract: | The product quality is a critical issue in the metal forming industry. Although many investigations have been conducted regarding the prediction of metal forming product defect and avoidance in macro scale, similar researches have barely been done in the micro scaled and few comparisons have been made between them. In this study, the axisymmetrical flanged components with four types of parameters are fabricated by extruding process both in macro and micro scale. The flow-induced folding defect formation mechanism is revealed by finite element (FEM) simulation and verified by the cold extrusion experiment. It is found that when the dimensions are scaled down, the metal flow behavior is influenced by the grains greater and the type of the defects changes as well. Also, the formation of the defect is very sensitive to the configuration of the components. By changing the tooling geometry, the defects can be avoided both in macro scale and micro scale. These metal flow behavior difference and the sensitivity of dimensions for the formation of the defect between the macro and micro scaled products provide useful guidelines for the investigation of size effect and the design of defect-free micro scaled metal formed product in the process design. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b2576827x.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.31 MB | Adobe PDF | View/Open |
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