科技英語(yǔ)作業(yè)

1、Magnetic microstructures of high Magnetic microstructures of high performance permanent magnetic performance permanent magnetic materialsmaterials 材化材化1202班班 070512xxxxxwilliam 班級(jí)班級(jí) 學(xué)號(hào)學(xué)號(hào) 姓名姓名班級(jí)班級(jí)Contentsmagnetic force microscopy high coercivity Nd-Fe-B sintered magnets hot-deformed Nd-Fe-B magnets 2

2、:17-type Sm-Co sintered magnets 4123Magnetic domains are strong correlated to the macro-magnetic propertiesof magnetic materials. . the process輕敲模式輕敲模式抬起模式抬起模式 magnetic force microscopy (MFM)1.第一次掃描采用輕敲模式，得第一次掃描采用輕敲模式，得到樣品在這一行的高低起伏并記到樣品在這一行的高低起伏并記錄下來(lái)；錄下來(lái)；2.然后采用抬起模式，讓磁性探然后采用抬起模式，讓磁性探針抬起一定的高度針抬起一定的高度(

3、通常為通常為10200nm)，并按樣品表面起伏軌，并按樣品表面起伏軌跡進(jìn)行第二次掃描，由于探針被跡進(jìn)行第二次掃描，由于探針被抬起且按樣品表面起伏軌跡掃描，抬起且按樣品表面起伏軌跡掃描，故第二次掃描過(guò)程中針尖不接觸故第二次掃描過(guò)程中針尖不接觸樣品表面（不存在針尖與樣品間樣品表面（不存在針尖與樣品間原子的短程斥力）且與其保持恒原子的短程斥力）且與其保持恒定距離（消除了樣品表面形貌的定距離（消除了樣品表面形貌的影響），磁性探針因受到的長(zhǎng)程影響），磁性探針因受到的長(zhǎng)程磁力的作用而引起的振幅和相位磁力的作用而引起的振幅和相位變化，因此，將第二次掃描中探變化，因此，將第二次掃描中探針的振幅和相位變化記錄下

4、來(lái)，針的振幅和相位變化記錄下來(lái)，就能得到樣品表面漏磁場(chǎng)的精細(xì)就能得到樣品表面漏磁場(chǎng)的精細(xì)梯度，從而得到樣品的磁疇結(jié)構(gòu)。梯度，從而得到樣品的磁疇結(jié)構(gòu)。 high coercivity Nd-Fe-B sintered magnetsEvolution of magnetic domains for sintered Nd-Fe-B magnets upon temperaturematerials magnetic microstructures ContentsThe different microstructures of different temperature,120，170，270

5、respectivelyHigh coercivity NdDyFeCoBAl permanent magnets were prepared by powder metallurgy procedures. Description of the contentsText in hereDifferent crystals appear white or dark in color,Nevertheless, these crystals are still in single domain stateThere is almost no contrast in them, indicatin

6、g that they are single domain .Text in herea number of crystals have already had plate-like domain structures (Fig. 2(c), which are formed by nucleation and growth of reversal domains.Text in hereThe magnetic contrast of the single crystals increases compared to Fig. b1b1abchot-deformed Nd-Fe-B magn

7、etsMagnetic domains of hot-pressed and hot-deformed Nd-Fe-B magnetsmaterials and environment sample surfaces ContentsOne is with surface normal parallel (/) to the press direction; the other is with surface normal perpendicular () to the press direction. 1、Nd13.62Fe75.70Co4.45B5.76Ga0.47 melt-spun r

8、ibbon powders2、 in argon atmosphere at temperatures about 850 C with different height-reduction (h) of 60% - 88%熱壓熱壓(Hot-press)和熱變形和熱變形(Die-upset)。熱壓階段將。熱壓階段將Nd-Fe-B粉末壓成高密度、各向同粉末壓成高密度、各向同性坯塊。熱變形階段將性坯塊。熱變形階段將Nd-Fe-B等軸晶轉(zhuǎn)變?yōu)槠瑺罹?，片狀等軸晶轉(zhuǎn)變?yōu)槠瑺罹В瑺罹У亩讯夥绞綖榇怪眽嚎s方向，晶的堆垛方式為垂直壓縮方向，c軸軸(易磁化軸易磁化軸) 沿著壓力方向沿著壓力方向排布，形成各向異

9、性磁體，從排布，形成各向異性磁體，從而大幅度提高磁體的磁性能而大幅度提高磁體的磁性能.2:17-type Sm-Co sintered magnetsmaterialsprocessenvironment1、The Sm(Co,Fe,Cu,Zr)z (z = 7.0 -8.5) permanent magnets2、 sintering at about 1200 for 0.5h, solid-solution treatment at about 1180 for 5 h, isothermal aging at 830 for 24 h, slow cooling at a rate o

10、f 0.7 /min to 400, and then soaking for 10 hA stripe domain pattern is presented. we gradually quenched specimens from 1200, 1180, 830 and 400 to room temperature, sequentially. Takes on typical corrugation and spike domains (i.e., black and white dots). Detected by magnetic tips as coarse domains o

11、r wide stripe domains.the domain structures are actually an aggregation of many single domains, or so-called coupling interaction domains(a)(b)(c)(d)Summary The influence of temperature, fabrication procedure parameters The thermal demagnetization process consists of four stagesTheir magnetic domains can be named as interaction ones.The domain configurations change from plate-like for the as-sintered magnet to corrugation and spike-like for the homogenized one, and then to a coarse, and finally to a finer domain structure .Nd-Fe-