Soft magnetic steel

Fig. 3 Experimental setup for etmtFollmg feiroilmd droplets. The eoils are etehed on a double-sided printed eircuit board. The gray eoils are (m the back of thePCB. The PCB is placed on a soft magnetic steel sheet with two permanent magnets at either side. The magnetic field of the two permanent magnets polarizes the magnetic particles in the ferrofluid droplet...

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. 

Silicon in the form of ferrosilicon is used in large quantities as a deoxidizing agent in steel manufacture. Silicon steel alloys are utilized as dynamo and transformer plates due to their soft magnetic properties, as machine tool steels, as spring steels and as corrosion resistant casting steels for chemical plant. 

OTHER COMMENTS replaced radium in experimental medicine and cancer research used as a trace element in fertilizers principal use is in alloys, especially cobalt steels for permanent and soft magnets. 

The physical basis of the use of Fe— Si alloys, commonly called silicon steels, as soft magnetic materials is the fact that both the magnetocrystalline anisotropy isTi and the magnetostriction parameters >.100 and Xm of Fe approach zero with increasing Si content (see Fig. 4.3-5a). The lower the magnitude of these two intrinsic magnetic properties is, the lower are the coercivity He and the AC magnetic losses The total losses ppe consist of the static hysteresis losses p y and the dynamic eddy current losses pw which may be subdivided into a classical p c and an anomalous p eddy current loss term. 

In the present study, the variation of magnetic core losses with temperature of a single readily-available soft magnetic material was obtained. For convenience, the core was constructed from the silicon steel punchings of a commercial 400 cycle per second power transformer, A... 

Pure iron is a silvery white, relatively soft metal and is rarely used commercially. Typical properties are Hsted in Table 1. Electrolytic (99.9% pure) iron is used for magnetic cores (2) (see Magnetic materials, bulk). Native metallic iron is rarely found in nature because iron which commonly exhibits valences of +2 and +3 combines readily with oxygen and sulfur. Iron oxides are the most prevalent form of iron (see Iron compounds). Generally, these iron oxides (iron ores) are reduced to iron and melted in a blast furnace. The hot metal (pig iron) from the blast furnace is refined in steelmaking furnaces to make steel... 

Soft, silvery metal whose isolation is difficult. Ytterbium fluoride is added to dental fillings (as X-ray contrast agent). Ytterbium is a constituent of rust-free special steels. Yb2Co13Fe3Mn holds the magnetic world record, but is too expensive for commercial purposes. The element is occasionally applied in nuclear medicine and radiography. It also activates phosphors that convert infrared rays into visible light. 

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