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Lord, A. E., Jr.

Publications and source records attributed to Lord, A. E., Jr..

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Calculation of the critical cooling rate for amorphous Pd/77.5/Si/16.5/Cu/6/

The viscosity of the molten alloy Pd(77.5)Si(16.5)Cu(6) has been determined from 744 to 1000 C using an oscillating cup viscometer. Using these data (together with other pertinent physical data available for this alloy) in existing crystallization theory indicates that it could be made amorphous at cooling rates as low as 5-10 K/sec. This analysis assumes strictly homogeneous nucleation. Containerless solidification will be one good testing ground for the results of this analysis.

Steinberg, J.↗
NASA NTRS1978

Uniform distribution of BeO particles in Be casting produced in rocket free fall

An experiment at zero-g aboard a NASA sounding rocket was conducted to evaluate the distribution of BeO particles in a Be casting. A distinction is drawn between the downward settling of particles in a quiescent melt, and the velocity gradient collisions of particles in a melt agitated by electromagnetic stirring. A similar experiment was conducted on earth using the same melting and solidification of a 0.922 cm spheroid of HIP-50 as was carried out in space; the only difference arising from the effect of gravity. Under zero-g conditions, the time needed for agglomeration was lengthened considerably, but the result was a casting of more uniform particle distribution.

Wouch, G.↗
NASA NTRS1978

Preparation of amorphous ferromagnetic materials through containerless solidification

The work reported herein consists of: (1) the ground based experiments; (2) the analysis of the ground based specimens; (3) the flight experiment; (4) failure to melt analysis; and (5) recommendations and conclusions. The ground based experimental work yielded new results in terms of understanding the viscoelastic properties of ferromagnetic metallic glasses and the variation of viscosity through the glass transition temperature from metallic glass to crystalline solid. This last result was of importance in predicting what glass can be produced at lower quench rates.

Lord, A. E., Jr.↗