Powder-in-tube process

R. L. Sabatini, T. R. Thurston, M. Suenaga A ki- 2.119 netic mechanism for the formation of aligned (Bi,Pb)2Sr2Ca2Cu3 0io in a powder-in-tube processed tape, Appl. Phys. Lett. 69, 580 (1996) 2.120... 

Bronze process Internal Tin (IT) process Powder-in-tube process (PIT)... 

Cables via the powder-in-tube (PIT) method The approach is especially suited to processing Bi-2223 into leads and cables for power applications. A silver or silver alloy tube, filled with the partially reacted precursor powders formulated to yield Bi-2223, is drawn down to a wire 1-2mm diameter. The wire is rolled into a tape if that is the required form, usually with a width-to-thickness ratio of approximately 10 1. The composite is then heated to 800-900 °C when the powder partially melts. The recrystallization process is controlled and the pure Bi-2223 phase develops with large grains oriented so that the Cu-O planes lie parallel to the silver surface to optimize Jc. 

The strongly anisotropic shape of the crystallites favors the development of a texture parallel to the surface of the Ag tube in powder-in-tube (PIT) processing, and this is highly desirable for the superconducting properties. The Ag content also serves as a source of pinning centers that hinder the flux line motion. 

To optimize the metallic effect, the conditions outlined in Section 14.4.4 under Injection Molding should be maintained. The pigments are added as compound, masterbatch, or powder. The use of static mixers or special mixing screws can improve the homogeneity of the blend. For the pinch tube process the high melt viscosity should be considered when preparing the masterbatch. 

The determinations of the solubility can be carried out in various ways- One of the simplest methods, which also gives sufficiently accurate results when the temperature is not high or when the solvent is not very volatile, can be carried out in the following manner. The solid substance is finely powdered (in order to accelerate the process of solution), and placed in sufficient quantity along with the solvent in a tube carefully closed by a glass stopper the latter is protected by a rubber cap, such as a rubber finger-stall. The tube is then rotated in a thermostat, the temperature of which does not vary more than one or two-tenths of a degree, until saturation is pro-... 

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