Analysis of powder compaction process through equal channel angular extrusion /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2010]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | A thermodynamic framework was presented for the development of powder constitutive models. The process of powder compaction through Equal Channel Angular Extrusion (ECAE) at room temperature was modeled using the finite element analysis package ABAQUS. The simulation setup was used to conduct a parametric study involving varying the process parameters of ECAE, aimed at aiding the process design. Two powder compaction models, the Gurson model and the Duva and Crow model, were used to test their efficacy in modeling this process. The thermodynamic framework was applied to derive the constitutive equations of the Duva and Crow model. Modeling parameters like friction coefficients, interaction conditions were determined by comparing the simulations for solid billet and an empty can with actual experimental runs for loads, shear angle and workpiece geometry. The simulations using the two powder constitutive models showed no significant difference in the stress in the powder during the extrusion. The results obtained from the 3-D simulations were also compared to experiments conducted to compact copper powder with a size distribution of 10m to 45m. It was found through experiments that the powder does not fully consolidate near the outer corner of the workpiece after the first ECAE pass and the results from the simulations were used to rationalize this phenomenon. Modifications made to the process by applying a back pressure during the simulations resulted in a uniformly compacted powder region. Further, simulations were carried out by varying the process parameters like the crosshead velocity, the friction coefficient between the walls of the die and the can, can dimensions and material, shape of the can cross section etc and the effect of each of these parameters was quantified by doing a sensitivity analysis. |
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| Item Description: | "Major Subject: Mechanical Engineering" Title from author supplied metadata (automated record created 2010-03-12 12:08:51). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |