Ten-Gram Levitation-Melted lngots

Abstract

Levitation of melts of about 10 grams in a protective atmosphere is described. There is a list, based on random experience, of materials that have been melted. Change of coil permits some temperature control. Shapes can be cast. There is a comparison with the technique of arc‐melting buttons, and a list of applications. An approximate formula for levitating force is given.

Some Stability Considerations in Levitation Melting

“…This is certainly valid for experiments performed near 0.5 MHz (8,9), and is a good approximation over a considerable range of lower frequencies. No analytic solution is known to Eq.…”

“…subject to the constraint Zal = 1 [4] An example of a perturbation which changes composition is exposure to ultraviolet radiation or chemical vapor (8). In this case, the OoJOs --O.…”

“…Most experimenters (3)(4)(5)8) have noted such limitations in mass for their particular apparatuses, and both Polonis (2) and Weisberg (9) have recorded the suspicion that this limitation should be implicit in the system, and some function of mass density and surface tension.…”

Phase Separation and Solid Solution in Nonstoichiometric and Stoichiometric (Sr, Mg)TiO3 Ceramics

“…By adjustment of the ring relative to the coil the liquid metal can be stabilized and steered to any desired position in the system. Many systems have been reported for the levitation of liquid metals in high frequency fields (Okress et al 1952, Polonis et al 1954, Comenetz and Salatka 1958, Harris and Jenkins 1959, Weisberg 1959, Begley et al 1959. These generally consist of a levitating coil in the form of a truncated cone tapering downwards, surmounted by one or more reversed turns in series with the levitating coil.…”

“…These generally consist of a levitating coil in the form of a truncated cone tapering downwards, surmounted by one or more reversed turns in series with the levitating coil. The reversed turns produce an opposing field which stabilizes the levitated specimen near the centre of the system (Okress et al 1952, Polonis et al 1954, Comenetz and Salatka 1958, Harris and Jenkins 1959, Weisberg 1959. Although such a system will work it is sensitive to unavoidable small differences in construction, and it is frequently found that in a batch of ostensibly identical coils one is found to be far superior.…”