Development of a Tabletop Model for the Generation of Amorphous/ Microcrystalline Metal Powders
Abstract
Electrohydrodynamics (EHD) was used as a basis for the generation and control of charged liquid droplets in order to produce micro-size powders and splat coatings. The EHD technique requires the use of intense electric fields to generate liquid droplets directly from the liquid state. This is achieved by delivering a molten alloy to the tip of a fine capillary nozzle to which high voltage is applied. Resistance heater technology was developed, resulting in greater reliability and temperatures of 1800K were achieved. Powders smaller than 0.01 micron have been produced with calculated cooling rates of approximately 10 to the 7th power K/s from radiation cooling alone. Several aluminum alloys were sprayed and produced small single spherical crystals, cicrystals, and adherent coatings. Amorphous powders and coatings (due to splat cooling) were formed using a Fe-Ni-B-P metallic glass alloy. Thin films were produced by EHD deposition of Si and Ge semiconductor materials. An Engineering Model was developed to study operation of an EHD powder generator using automation and modern computer techniques. Results of these studies were used to design, construct, and deliver a Micro-Particle Processor for use as a research instrument for experimentation with fine powders, and the production of coatings and thin films, involving rapid solidification.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1982
- Accession Number
- ADA120584
Entities
People
- Bernard E. Kalensher
- John F. Mahoney
- Julius Perel
- Scott Taylor
- Zef Shanfield