The Strain Rate Dependence of the Impact Properties of Type 316L Powder Compacts
| Autor: | Tsung-Ju Liu, 劉宗儒 |
|---|---|
| Rok vydání: | 2004 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 A Split-Hopkinson bar is used to investigate the strain rate influence of the impact properties of Type 316L powder compacts. Mechanical testing is performed at room temperature under strain rates ranging from 2700s-1 to 7500s-1. Optical microscopy and scanning electron microscopy techniques are used to analyze the fracture and microstructure characteristics of the deformed specimens to determine the relation between mechanical and microstructural properties. Experimental results indicate that strain and strain rate influence mechanical properties of Type 316L powder compacts. At room temperature, flow stress and strain rate sensitivity increase with increasing strain rate, but activation volume and work hardening coefficient decrease. From fractographic analysis, we find fracture occurs after shear band formation. We also find dimple characteristics on fracture surfaces. The Khan-Huang-Liang constitutive equation with the experimentally determined specific material parameters successfully describes the flow behaviour of Type 316L Powder Compacts for the tested conditions. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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