Permalloys

Nickel, used extensively to make coins and nickel steel for armor plates and burglar-proof vaults, and is also a component in Nichrome(R), Permalloy(R), and constantan. 

Monuron Monzomte Moody diagram Mooney viscometer Mooney viscometers MOPAC 5.0 benchmark 4-79Mo-Permalloy Mopping asphalt Morantel [20574-50-9]... 

Squalene epoxidation Squaraine Square 50 Square 80 Square permalloy Square Permalloy 80 Squaric acid [2892-51-5]... 

Soft magnetic materials are characterized by high permeabiUty and low coercivity. There are sis principal groups of commercially important soft magnetic materials iron and low carbon steels, iron—siUcon alloys, iron—aluminum and iron—aluminum—silicon alloys, nickel—iron alloys, iron-cobalt alloys, and ferrites. In addition, iron-boron-based amorphous soft magnetic alloys are commercially available. Some have properties similar to the best grades of the permalloys whereas others exhibit core losses substantially below those of the oriented siUcon steels. Table 1 summarizes the properties of some of these materials. 

Fig. 7. Hysteresis loops at 60 Hz of three commercial Ni—Fe alloys A, Orthonol B, AHoy 48 and C, Permalloy 80. To convert A/m to Oe, divide by 79.58.

Fig. 1. The effect of (------) coercive force, ( ) lesistivity, and ([[aitl]]) magnetoiesistance coefficient foi Permalloy films (a) at a constant argon...

Only about 10 elements, ie, Cr, Ni, Zn, Sn, In, Ag, Cd, Au, Pb, and Rh, are commercially deposited from aqueous solutions, though alloy deposition such as Cu—Zn (brass), Cu—Sn (bronze), Pb—Sn (solder), Au—Co, Sn—Ni, and Ni—Fe (permalloy) raise this number somewhat. In addition, 10—15 other elements are electrodeposited ia small-scale specialty appHcations. Typically, electrodeposited materials are crystalline, but amorphous metal alloys may also be deposited. One such amorphous alloy is Ni—Cr—P. In some cases, chemical compounds can be electrodeposited at the cathode. For example, black chrome and black molybdenum electrodeposits, both metal oxide particles ia a metallic matrix, are used for decorative purposes and as selective solar thermal absorbers (19). 

Electroless Electrolytic Plating. In electroless or autocatalytic plating, no external voltage/current source is required (21). The voltage/current is suppHed by the chemical reduction of an agent at the deposit surface. The reduction reaction must be catalyzed, and often boron or phosphoms is used as the catalyst. Materials that are commonly deposited by electroless plating (qv) are Ni, Cu, Au, Pd, Pt, Ag, Co, and Ni—Fe (permalloy). In order to initiate the electroless deposition process, a catalyst must be present on the surface. A common catalyst for electroless nickel is tin. Often an accelerator is needed to remove the protective coat on the catalysis and start the reaction. 

Style Permalloy Ferrite Gapped Shielding Cost Cost... 

A range of metals including iron, copper, cobalt, permalloy and nickel were used to form conductive and paramagnetic coatings on the halloysite clay. These conductive small particles may then be used in polymeric systems to form composites with interesting electromagnetic properties. 

Another area with a large research activity is also related to computer technology. It is electrodeposition of magnetic alloys for thin-film recording heads and magnetic storage media. Here new magnetic materials are needed that have properties superior to those of electrodeposited NiEe (Permalloy). These activities are reviewed by Andricacos and Romankiw (25) and Romankiw (32). 

Contains levels of nickel which vary widely in content. Commercial products include Invar and Permalloy. These alloys are used in certain high-level technology applications such as transoceanic cabling and other applications whereby machining tolerances are exact, such as clocks and variable condensers. 

Magnetically soft Fe-Ni alloys can have their properties altered by heat treatment. The compound NisFe undergoes an order-disorder transformation at about 500°C. Since the susceptibility of the ordered phase is only about half that of the disordered phase, a higher susceptibility is realized when the alloy is quenched from 600°C, a process that retains the high-temperature, disordered structure. Heat treatment of Fe-Ni alloys in a magnetic field further enhances their magnetic characteristics (see Figure 6.61), and the square hysteresis loop of 65 Permalloy so processed is desirable in many applications. A related alloy called Supermalloy (see Table 6.19) can have an initial susceptibility of approximately one million. 

Figure 6.61 Hysteresis loop for Permalloy 65 heat treated with and without an applied magnetic field. From K. M. Ralls, T. H. Courtney, and J. Wuhf, Introduction to Materials Science and Engineering. Copyright 1976 by John Wiley Sons, Inc. This material is used by permission John Wiley Sons, Inc.

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