Material Forming Processes
This text covers techniques such as injection molding, composites forming, die extrusion, hydro-forming, blowing, forging, machining and cutting, super plastic forming, as well as a number of other specific processes.
TABLE OF CONTENTS Material Forming Processes
Chapter 19: Analysis of Material Behaviour at High Strain Rates for Modeling Machining Processes
Paolo Bariani and Stefano Corazza
DIMEG, University of Padova, Italy
Guido Berti
DTG, University of Vicenza, Italy
1. Introduction
Accurate measurement of the material response to high strain-rate deformation is a prerequisite both for accurate analysis and for modeling metalworking processes. In typical machining processes, both strain and strain rate, as well as temperature, vary over a wide range as shown in Table 1 [JAS 99]. In particular in the plastic zone the material can reach very high strain rates, above those that can be investigated using currently available methods based on traditional ordinary mechanical and hydraulic devices. SHPB technique allows rates of straining of 300 10 4 s -l to be reached.
| Material | Temperature [C] | Strain | Strain rate [1/s] |
|---|---|---|---|
| Al 6062 T6 | 20 400 C | 1 2 | 10 3 10 5 |
| AISI 1045 | 20 600 C | 1 3 | 10 3 10 5 |
This work aims to investigate material behaviour under conditions similar to those experienced during machining processes (temperature, strain and strain rate).
2. Conditions influencing material response in the machining process
2.1. Strain
In machining, operation energy consumption is mainly the result of two phenomena: shearing in the flow separation zone (primary shear zone) and chip formation (secondary shear zone). The most critical conditions, in terms of strain, strain rate and...
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