Dynamic Consolidation of Metal Powders.
Abstract
We have studied the shock wave consolidation of copper, 4330 steel and aluminum+6% silicon powders. We measured the Hugoniots of the unsintered powders using piezoresistive pressure sensors as well as impedance matching techniques and found that they can be well described by available models for pore collapse. An elementary model for the surface heating was developed based on the flux of energy at the interfaces between powder particles during compaction. This model was found to agree quantitatively with observations of localized microstructural modifications in recovered specimens. We found that most of the energy of the compaction shock is deposited at the particle interfaces and that powder particle morphology and specific surface area are important variables. Localized thermal modifications can be either solid state transformations or surface melting and rapid cooling can produce metastable structures. Knowledge of the shock history is essential to the interpretation and control of the consolidated microstructure. We have produced and tested consolidated aluminum+6% silicon that has tensile properties comparable to those of wrought material.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 25, 1988
- Accession Number
- ADA192126
Entities
People
- William H. Gourdin
Organizations
- Lawrence Livermore National Laboratory