ULTRASONIC HOT PRESSING OF METALS AND CERAMICS

Technical Report · Fri Dec 01 04:00:00 EST 1961

OSTI ID:4792799

Tarpley, W B; Kartluke, H

The feasibility of ultrasonic hot pressing was demonstrated on silver, calcium fluoride, and aluminum oxide powders. A hermetically-sealable, force- insensitive acoustic mounting system was used to penetrate into the high-pressure (up to 5000 psi) and high-temperature (up to 2550 deg F) controlled atmosphere environment. The density of silver powder compacts was increased as much as 1.6 times that of the nonultrasonic controls. Reductions in the tenmperature or in the pressure necessary to achieve comparable density were observed with ultrasonic activation under otherwise constant conditions. Similar results were obtained with calcium fluoride; the densities of ultrasonically aetivated specimens were comparable to controls requiring 200 to 300 deg F higher temperatures. Submicron aluminum oxide powder was ultrasonically hot pressed with graphite tooling. A 13% improvement in density was achieved as a result of ultrasonic activation under isothermal conditions at the normal 4-hr pressing time. With 2-hr ultrasonic pressing, at temperatures 250 deg F lower than the 4- hr controls, it was also possible to produce equivalent density. With further evolution of the hot-pressing array, increased-magnitude effects may be expected. A number of undesirable side effeets of high-temperature hot pressing may be avoided through ultrasonic activation. (auth)

• Research Organization: Aeroprojects, Inc., West Chester, Penna.
• NSA Number: NSA-16-010484
• OSTI ID: 4792799
• Report Number(s): NYO-10007
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM OXIDES
CALCIUM FLUORIDES
CERAMICS
COMPACTING
CONTROL
DENSITY
EFFICIENCY
GRAPHITE
HIGH TEMPERATURE
HOT WORKING
INERT GASES
MACHINE PARTS
METALS
METALS, CERAMICS, AND OTHER MATERIALS
POWDERS
PRESSURE
SEALS
SILVER
STANDARDS
TEMPERATURE
THICKNESS
TOOLS
ULTRASONICS