高Fe含量FeCuNbSiB系非晶/纳米晶合金制备及其磁性研究

研究了过渡金属元素(Zr,Nb,Mo)和Cu元素对Fe78Si9B13合金系非晶形成能力、热稳定性和磁性的影响;在Fe74Cu1Nb3Si13B9合金的基础上,通过逐步提高Fe含量,利用单辊甩带法制备Fe(76+x)Cu1Nb3Si(11-x)B9(x=0,2,4)和Fe(79+x)Cu1Nb2Si(6-x)B12(x=0,2,4)非晶/纳米晶合金薄带;利用XRD、DSC、TEM和VSM研究了高Fe含量Fe-Cu-Nb-Si-B系非晶/纳米晶合金的微观结构和磁性,并通过添加Nb元素优化了高Fe含量合金的磁性。研究结果表明:Zr和Nb元素的添加能明显提高Fe78Si9B13合金的非晶形成能力和热稳定性;高Fe含量的Fe-Cu-Nb-Si-B系纳米晶合金为典型的非晶/纳米晶双相结构,合金的饱和磁化强度Ms180 emu/g,且合金的矫顽力Hc在2Oe-9Oe之间,具有良好的软磁性能;Nb元素能显著细化Fe-Cu-Nb-Si-B系合金晶粒尺寸,从而能显著降低合金的矫顽力,改善合金的软磁性能;当Fe含量在80%-83%(原子百分比,下同)之间时,合金具有良好的软磁性能,但当Fe含量达到85%时,会有Fe2B、Fe3B相析出,从而显著恶化其软磁性能。     

高能球磨技术制备Fe_(78-x)MxSi_(13)B_9磁性材料

采用高能球磨技术制备Fe78-xMxSi13B9软磁非晶合金粉体,利用X射线衍射仪、差示扫描量热分析仪、扫描电镜和振动样品磁强计分析过渡金属元素M(Zr、Nb、Mo)的添加对合金粉体微观组织结构、热稳定性及软磁性能的影响。结果表明,Zr、Nb的添加有利于Fe-Si-B系合金的非晶转变,其最大过冷液相区ΔTx为70.62 K,玻璃转变温度Tg和开始晶化温度Tx分别为785.05、855.67 K;饱和磁化强度Ms为111 emu/g,矫顽力Hc约为2 028.443 A/m。     

Nb和Si元素对提高纳米晶带材抗氧化能力研究

采用SEM和XRD等手段分析了Fe82Cu1B12Si4 Nb1与Fe73.5 Cu1 B7 Si15.5 Nb3纳米晶合金带材在空气中灼烧后的晶化产物和氧化产物;通过降低Nb和Si元素含量,提高Fe和B元素的含量,虽然使Fe82Cu1 B12 Si4 Nb1纳米晶合金具有高饱和磁感应强度和低的矫顽力,但却降低了它的非晶形成和抗氧化能力。根据K.Hono等采用原子探针法观察到的在晶化过程中各元素分布情况,提出了一个晶化过程模型,通过模型分析了纳米晶合金的抗氧化能力的原因;随着晶化过程推进,残余非晶相中Nb元素含量增加,使得残余非晶相区的晶化温度提高,同时发挥限制晶体长大的作用。     

热处理温度对非晶合金耐蚀性能的影响

目的 在非晶合金过冷液相区范围内研究热处理温度对非晶合金耐蚀性能的影响。方法 采用差示扫描量热法来表征非晶合金，并作出非晶合金的差热曲线，以此来确定非晶合金的玻璃化转变温度Tg和晶化温度Tx，进而求出其过冷液相区范围，以此来确定热处理退火温度范围。随后在过冷液相区范围内均匀选取3个不同温度点对非晶合金进行热处理，最后在质量分数为3.5%的NaCl溶液中对非晶合金进行电化学测试，并与未处理样品进行比较，进而发现其耐蚀性规律。结果 经过不同的热处理后，非晶合金在质量分数为3.5%的NaCl溶液中的电化学腐蚀结果相差较多。结论 在保温时间和冷却方式不变时，随着热处理温度的增加，非晶合金的耐蚀性呈下降趋势。退火温度为540 ℃时，非晶合金的耐蚀性能最佳。     

Fe74Al4Ga2P12B4Si4块体非晶合金的纳米晶化及软磁性能研究

采用铜模铸造法制备了厚2mm的Fe74Al4Ga2P12B4Si4块体非晶合金.利用X射线衍射(XRD)、差热分析(DSC)和振动样品磁强计(VSM)研究了其晶化行为和软磁性能.结果表明,非晶合金的玻璃转变温度Tg为457.35℃,晶化开始温度Tx为497.65℃.合金的过冷液相区宽度△Tx达到40.30℃,表明合金具有较大的玻璃形成能力.F74Al4Ga2P12B4Si4合金的晶化是二级晶化过程.经520℃等温退火后析出α-Fe相,其晶粒尺寸为15.9nm;而经550℃等温退火后析出α-Fe相及微量的A10.3Si0.7Fe3和Fe3B相,其中α-Fe相的晶粒尺寸为17.4nm.非晶合金的饱和磁化强度为108.816emu/g、矫顽力Hc为574.97Oe;经520℃等温退火后,纳米晶合金的饱和磁化强度为106.875emu/g、矫顽力Hc为94.16Oe.退火实验结果表明,纳米晶化对材料的饱和磁化强度没有显著影响,但会显著降低材料的矫顽力.     

ZT3非晶合金在过冷液相区的塑性变形研究

目的 研究不同的应变速率和变形温度对Zr30.2Ti32.9Cu9Ni5.3Be22.6非晶合金(亦称ZT3)在过冷液相区塑性变形行为的影响。方法 首先，用真空非自耗电弧炉熔炼合金锭并吸铸成直径为8 mm、长度为60~80 mm的非晶合金圆棒;然后，通过等温晶化试验确定ZT3非晶合金在过冷液相区中对应不同温度时发生晶化转变所需的最短时间，并用热模拟试验机进行压缩变形的试验研究;最后，用X射线衍射仪测试ZT3非晶合金在过冷液相区塑性变形后的组织特性。结果 ZT3非晶合金在过冷液相区内的塑形变形行为与应变速率和变形温度有密切的关联性。不同的应变速率与变形温度都会对其塑性变形产生影响，但变形温度的影响比恒定应变速率更大。对ZT3非晶合金变形后的结构分析发现，应变速率对非晶态结构的影响大于温度。结论 ZT3非晶合金的等温晶化转变孕育时间最短为17 min，在小于17 min的时间内完成塑性变形即可抑制晶化转变的发生。当恒定应变速率为2×10^?3 s^?1时，将变形温度控制在355~375 ℃范围内有利于ZT3非晶合金在过冷液相区进行热压塑性成形。     

CuZrNb块体金属玻璃的形成能力和低温电阻的研究

采用铜模吸铸方法制备出直径为1mm的Cu60Zr40-xNbx(x=2,5,8)合金。对合金的结构分析表明,Nb含量的改变对合金非晶形成能力有很大影响,当Nb含量为5%(原子百分比)时,合金可以形成完全非晶。低温电阻测试结果表明,Nb含量的变化会明显改变合金的低温电阻率,Nb含量为2%时,合金的电阻率随温度下降而上升,而含量为5%和8%时,电阻率随温度下降而下降。与晶化前相比,Cu60Zr35Nb5块体金属玻璃晶化后电阻率较晶化前有所降低,在低温时由非晶态的部分超导转变为晶化态的超导。     

（FexCo1-x）73.5Cu1Nb3Si13.5B9合金高温磁性的研究

研究了460～640℃等温退火后纳米晶（FexCo1-x）73.5Cu1Nb3Si13.5B9（x=0.5，1）合金的初始磁导率麒随温度变化。与双相纳米晶Fe73.5Nb3Si13.5B9合金相比，（Fe0.5Co0.5）73.5Cu1Nb3Si13.5B9合金室温下的磁导率降低，但晶化相和非晶相居里温度明显升高，并显著提高了合金在高温下的软磁性能。初步探讨了改善纳米晶合金高温磁性的机理。     

具有宽过冷液相区的Fe63Co7NbxZr10—xB20非晶态合金的热稳定性和磁性研究

利用单辊急冷法制备出厚约35μm宽5mm的Fe63Co7NbxZr10-xB20条带，并研究了合金的热稳定性、非晶结构和磁性能。结果表明，含4at%Nb的Fe63Co7Nb4Zr6B20合金过冷液相区ΔTx最宽，达到79K。合金系的饱和比磁化强度σs随着Nb含量的增加而线性减小。合金系经973K退火900s，由于α-Fe等相的析出，使得合金的σs和Hc均迅速升高。     

(Fe50Co50)73.5Cu1Nb3Si13.5B9合金的微观结构及软磁性能

研究了(Fe50Co50)73.5Cu1Nb3Si13.5B9合金晶化过程中的微观结构及形成纳米晶后的合金软磁性能,发现在FINEMET合金基础上,用Co置换1/2含量Fe形成的(Fe50Co50)73.5Cu1Nb3Si13.5B9非晶合金具有相对较高居里温度Tc≈450℃,460℃退火处理后(Fe50Co50)73.5Cu1Nb3Si13.5B9合金形成均匀纳米晶组织,晶粒度约为20nm.     

Influence of Small Cr Addition on Thermal Stability and Magnetic Properties of Fe-Co-Zr-Nb-B Glassy Alloys

Fe62Cos-xCrxZr6Nb4B20 （x=0-4 at. pct） metallic glasses show high thermal stability with a maximum supercooled liquid region of about 84.8 K. The addition of 2 at. pct Cr causes the extension of the supercooled liquid region remarkably, leading to the enhancement of thermal stability and glass-forming ability. The crystallization of the Fe-based glassy alloys takes place through a single exothermic reaction, accompanying the precipitation of more than three kinds of crystallized phases such as α-Fe, Fe2Zr and ZrB2. The long-range atomic rearrangements required for the precipitation of the multiple crystalline phases seem to play an important role in the appearance of the large supercooled liquid region through the retardation of the crystallization reactions. The Fe-based alloys exhibit soft ferromagnetic properties. The saturation magnetization decreases with increasing Cr content while the saturated magnetostriction increases as a function of Cr content. There is no distinct change in the saturation magnetization and coercive force with annealing temperature below the crystallization temperature. The devitrification gives rise to a considerable enhancement in both as and He.     

Ferromagnetic Fe-based Amorphous Alloy with High Glass-forming Ability

A ferromagnetic amorphous Fe73Al4Ge2Nb1P10C6B4 alloy with high glass-forming ability was synthesized by melt spinning. The supercooled liquid region before crystallization reaches about 65.7 K. The crystallized structure consists of alpha -Fe, Fe3B, FeB, Fe3P and Fe3C phases. The Fe-based amorphous alloy exhibits good magnetic properties with a high saturation magnetization and a low saturated magnetostriction. The crystallization leads to an obvious decrease in the soft magnetic properties.     

Effect of composition on the crystallization and magnetic properties of Fe–Co–Si–B–Nb amorphous alloys

The crystallization behavior and magnetic properties of Fe₆₂Co₁₀Si_15−x B_18−y Nb_{(x + y)−5} amorphous alloys with x = 0–5 and y = 0–5 were examined. Primary crystallization temperature of Fe₆₂Co₁₀Si_15−x B₁₃Nb _x and Fe₆₂Co₁₀Si₁₀B_18−y Nb _y alloys increased with the addition of Nb. The primary and secondary crystallization temperatures were well separated when the Nb content is above 4 at%. The alloys with 15–18 at% B showed a distinct supercooled region. The Nb addition decreased the Curie temperature as well as room temperature saturation magnetization. The glassy-type Fe₆₂Co₁₀Si₁₀B₁₈ alloy exhibited good soft magnetic properties as well as a supercooled liquid region of 39 K. The finding of the glassy-type Fe-based alloy without Nb element exhibiting high Bs above 1.4 T is promising for future use as a soft magnetic glass material.     

Effect of metalloids on crystallization and magnetic behaviour of FeCoSiB based metallic glass

A series of amorphous iron-cobalt alloys with varying metalloid, boron and silicon contents were studied for their thermal stability and magnetic behaviour. The crystallization temperature and thermal stability increased with the silicon content. Good soft magnetic properties were observed for the materials with nominal composition, (Fe_0.79Co_0.21)77Si_12.2B_10.8. The magnetic properties were further improved by annealing.     

Glass-Forming Ability for Nd_(70-x)Fe_(20)Al_(10)Y_x and Nd_(60-x)Fe_(30)Al_(10)Y_x Alloys

The glass-forming ability (GFA) of Nd70-xFe2oAl10Yx and Nd60-xFe30Al10Yx (0< x <15) alloys produced by Cu mold casting was investigated. Except Y=5 at. pct, bulk amorphous Nd70-xFe20Al10Yx alloys up to 2 mm in diameter were obtained. The GFA for Nd60-xFe30Al10Yx alloys, however, was found to decrease with increase of Y due to the increasing compositional deviation from the original eutectic point of Nd60Fe30Al10 alloy. The Nd60Fe20Al10Y10 and Nd60Fe30Al10 alloy exhibit the largest GFA and can be cast into bulk amorphous cylindrical specimens of 3 mm in diameter. The melting temperature or/and the reduced crystallization temperature is closely related to the GFA of Y-containing alloys. The bulk amorphous cylinder for the Nd55Fe20Al10Y15 alloy shows a distinct glass transition temperature and a wide supercooled liquid region before crystallization. The crystallization temperature, Tg, and the supercooled liquid region, TX, are 776 K and 58 K, respectively. The GFA and thermal stability of the Nd-Fe-AI-Y a     

Glass-Forming Ability for Nd70-xFe20AlioYx and Nd60-xFe30Al10Yx Alloys

The glass-forming ability (FGA) of Nd70-xFe20Al10Yx and Nd60-xFe30Al10Yx(0≤x≤15) alloys produced by Cu mold casting was investigated.Except Y=5 at.pct,bulk amorphous Nd70-xFe20Al10Yx alloys up to 2mm in diameter were obtained.The GFA for Nd60-xFe30Al10Yx alloys,however,was found to decrease with increase of Y due to the increasing compositional deviation from the original eutectic point of Nd60Fe30Al10 alloy.The Nd60Fe20Al10Y10 and Nd60Fe30Al10 alloy exhibit the largest GFA and can be cast into bulk amorphous cylindrical specimens of 3mmm in diameter.The melting temperature or /and the reduced crystallization temperature is closely related to the GFA of Y-containing alloys.The bulk amorphous c ylinder for the Nd55Fe20Al10Y15 alloy shows a distinct glass transition temperature and a wide supercooled liquid region before crystallization.The crystallization temperature,Tg,and the supercooled liquid region,ΔTx,are 776K and 58K,respectively,The GFA and thermal stability of the Nd-Fe-Al-Y alloys were discussed.     

新型Zr-Nb基大块非晶合金的形成及性能

本文用水淬法制备 Zr-Nb基大块非晶合金 ;并采用 DSC热分析法测定了该种合金的玻璃转变温度和热稳定性 ;采用超声检测方法精确测定了材料的声学性能 ,由此计算得到一组大块非晶合金的弹性性能参数。     

稀土La改性铁基非晶带材组织结构与软磁性能研究

主要研究掺杂了不同含量稀土La后的铁基非晶带材Fe73.5Cu1Nb3Si13.5B9非晶带材组织结构与软磁性能.结果表明,随着稀土La掺杂含量的增加,Fe73.5Cu1Nb3Si13.5B9非晶带材的Fe-Si相的析出温度下降,而Fe-B相的析出温度则升高,一方面,非晶的热稳定性下降,另一方面,有利于控制Fe73.5...     

铁钴镍基非晶态软磁材料的研究

研究了１０钟以铁钴镍为基的非昌态软磁材料，对非晶态合金的成分，熔点，晶化温度，居里温度及一些磁性能作了分析比较、将将材料制成元件装到电子镇流器上试验，研究结果表明，铁磁元素铁钴镍的含量比例，是影响非晶态磁性的主要因素；类金属元素对软磁材料的磁性能也有一定的影响，含磷的非晶态合金的熔点，晶化温度及居里温度比含碳的较高。