Magnetostriction: Yadda ake Musta da Zafi na Makamaci
Akwai hanyar irin da ake kira magnetostriction, wanda ya haɗa da abubuwa masu magana a matsayin cewa yana ƙunshi wani abu mai magana a kan tashin magana don in yi ƙarin ko ƙarami tsawon ruwa ko inganci a matsayin maɗara. Babban daɗi da inganci na abin da suka samu magnetostriction yana ƙunshi tsari da ƙwarewa na tashin magana, da kuma alamar magana da tsarin kusa da abin da suka samu.tashin magana, da kuma alamar magana da tsarin kusa da abin da suka samu.
Za a iya amfani da magnetostriction don in bincike energiya mai tashin magana zuwa energiya mai ƙaramin ruwa, ko kuma zuwa ƙaramin ruwa zuwa tashin magana, da kuma ita ce mafi girman tushen da ake amfani da su kamar actuators, sensors, transducers, transformers, motors, da generators.
Me Da Magnetostriction?
An samu magnetostriction a shekarar 1842 ta James Joule idan an samu cewa zane da kyau a cikin jerinin ironi ya ƙara tsawon ruwa a lokacin da an magance ta a gaba-gabanta, da kuma ya ciyar tsawon ruwa a lokacin da an magance ta a faɗa. Wannan matsala ana kiransa da ake kira "Joule's effect", da kuma ana samun shi a kafin daɗi na ferromagnetic materials (abubuwa masu magana a kan tashin magana) da kuma wasu ferrimagnetic materials (abubuwa masu duwatsu na magana).
Al'adu na duniya a kan magnetostriction yana ƙunshi tsarin kusa da abin da suka samu, wanda akwai ƙasashe masu ƙaramin magana. Kullum ƙasa na da tsari na magana, wanda ya faruwa ne daga balancin energy na magnetic anisotropy (kamfanin abin da suka samu tsarin magana) da kuma energy na magnetostatic (kamfanin abin da suka samu tsarin magana).
Idan an magance tashin magana a kan abin da suka samu, za a iya bayar da ƙoƙari ga ƙasashe, wanda ya haɗa da ƙasashe suka dole da tsari na magana. Wannan yanayin ya haɗa da ƙoƙari ga ƙasashe da kuma ƙaramin tsarin kusa da abin da suka samu. Saboda haka, abin da suka samu ya ƙara tsawon ruwa ko inganci a kan magnetostrictive strain (babban daɗi da inganci na abin da suka samu).
Babban daɗi da inganci na abin da suka samu yana ƙunshi:
Tsari da ƙwarewa na tashin magana
Saturation magnetization (babban daɗi da suka samu magana)
Magnetic anisotropy (kamfanin tsarin magana)
Magnetoelastic coupling (yaki a kan magana da elastic strain)
Temperature da stress state na abin da suka samu
Babban daɗi da inganci na abin da suka samu ya zama da ƙaramin ruwa ko ƙarin ruwa, da kuma abubuwa masu ƙaramin ruwa a lokacin da an magance su a kan tashin magana mai ƙaramin ruwa, wanda ana kiransa da ake kira Villari reversal.
Za a iya ƙirƙira babban daɗi da inganci na abin da suka samu a kan hanyoyin da dama, kamar optical interferometry, strain gauges, piezoelectric transducers, ko kuma hanyoyin resonant. Mafi girma parameter da ake amfani da su don in taimaka da magnetostriction shine magnetostriction coefficient (ko kuma Joule’s coefficient), wanda ake kiran da ita ce:
λ=LΔL
ida ΔL shine ƙaramin tsawon ruwa na abin da suka samu a lokacin da an magance ta daga zero zuwa saturation, da kuma L shine tsawon ruwa na farko.
Abubuwan Magnetostrictive
Akawo abubuwa masu samun magnetostriction, amma wasu daga cikinsu suna da ma'aikata masu ƙaramin ruwa da kuma ba da aiki da dabara. Wasu misalai na abubuwan magnetostrictive shine:
Iron: Iron shine mafi girman da ake amfani da su a kan abubuwan magnetostrictive, saboda ma'aikatar saturation magnetization da cost. Amma iron ya haɗa da wasu batunai, kamar magnetostriction coefficient (kusan 20 ppm), high hysteresis loss (energy dissipated during each cycle of magnetization), and high eddy current loss (energy dissipated due to induced currents in conductive materials in the material). Iron also has a low Curie temperature (the temperature above which a material loses its ferromagnetic properties), which limits its use in high-temperature applications.
Nickel: Nickel has a higher magnetostriction coefficient than iron (about 60 ppm), but also a higher hysteresis loss and eddy current loss. Nickel also has a low Curie temperature (about 360 °C) and is prone to corrosion.
Cobalt: Cobalt has a moderate magnetostriction coefficient (about 30 ppm), but a high saturation magnetization and a high Curie temperature (about 1120 °C). Cobalt also has a low hysteresis loss and eddy current loss, making it suitable for high-frequency applications.
Iron-Aluminum Alloy (Alfer): This alloy has a high magnetostriction coefficient (about 100 ppm), a high saturation magnetization, and a high Curie temperature (about 800 °C). It also has a low hysteresis loss and eddy current loss, and good mechanical properties. However, it is difficult to fabricate and requires special heat treatment.
Iron-Nickel Alloy (Permalloy): This alloy has a low magnetostriction coefficient (about 1 ppm), but a high saturation magnetization and a high permeability (the ability of a material to support an internal magnetic field). It also has a low hysteresis loss and eddy current loss, making it ideal for magnetic shielding and recording applications.
Cobalt-Nickel Alloy: This alloy has a moderate magnetostriction coefficient (about 20 ppm), but a high saturation magnetization and a high Curie temperature (about 950 °C). It also has a low hysteresis loss and eddy current loss, and good corrosion resistance.
Iron-Cobalt Alloy: This alloy has a moderate magnetostriction coefficient (about 30 ppm), but a very high saturation magnetization and a high Curie temperature (about 980 °C). It also has a low hysteresis loss and eddy current loss, and good mechanical properties.
Cobalt-Iron-Vanadium Alloy (Permendur): This alloy has a low magnetostriction coefficient (about 5 ppm), but a very high saturation magnetization and a very high Curie temperature (about 1400 °C). It also has a low hysteresis loss and eddy current loss, making it suitable for high-power applications.
Ferrites: Ferrites are ceramic materials composed of iron oxides and other metal oxides, such as cobalt oxide or nickel oxide. They have low magnetostriction coefficients (less than 10 ppm), but also low saturation magnetization and low permeability. They have very low hysteresis loss and eddy current loss, making them ideal for high-frequency applications. They also have high Curie temperatures (above 400 °C) and good corrosion resistance.
Rare Earths: Rare earths are elements with atomic numbers from 57 to 71, such as lanthanum, cerium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium. They have very high magnetostriction coefficients (up to 1000 ppm), but also very high hysteresis loss and eddy current loss. They have moderate saturation magnetization and permeability, but low Curie temperatures (below 300 °C). They are often used in combination with other metals or compounds to form alloys or intermetallics with improved properties.
Terfenol-D: Terfenol-D is an intermetallic compound composed of terbium, iron, and dysprosium. It has the highest magnetostriction coefficient ever recorded (about 2000 ppm), which means that it can produce very large strains when magnetized. It also has a high saturation magnetization and a high Curie temperature (about 380 °C). However, it also has a very high hysteresis loss and eddy current loss, which limits its efficiency and frequency range. It also requires a high magnetic field (about 800 kA/m) to reach its maximum strain, which increases its power consumption and cost.
Galfenol: Galfenol is an alloy of iron and gallium, with a composition of about Fe81Ga19. It has a moderate magnetostriction coefficient (about 250 ppm), but a very low hysteresis loss and eddy current loss, which make it more efficient and durable than Terfenol-D. It also has a high saturation magnetization and a high Curie temperature (about 700 °C). It can operate at low magnetic fields (about 100 kA/m) and high frequencies (up to 10 kHz).
Metglas: Metglas is a metallic glass composed of iron, boron, silicon, and other elements. It has a low magnetostriction coefficient (about 20 ppm), but a very high saturation magnetization and a very high permeability. It also has a very low hysteresis loss and eddy current loss, making it ideal for magnetic shielding and power conversion applications.
Tushen Magnetostriction
Magnetostriction na tushen da dama a kan siffofin da dama, kamar:
Actuators: Actuators are devices that convert electrical energy into mechanical motion, or vice versa. Magnetostrictive actuators use magnetostrictive materials to produce linear or rotary motion when subjected to a magnetic field or to generate a magnetic field when subjected to mechanical stress. Magnetostrictive actuators have advantages over other types of actuators, such as
