铁基非晶合金的辐照性能

铁基非晶合金由于成本低较、易制备、较好的温度稳定性等优点,并具优异的机械性能、磁性能和耐腐蚀性能而被广泛研究.并且其固有的无序结构有助于抵抗辐照导致的损伤,使得铁基非晶合金可作为抗辐照材料使用.辐照既可以试验铁基非晶合金的性能也是优化铁基非晶合金结构和性能的有效方法.本文综述了铁基非晶合金中子辐照、离子辐照和电子辐照性能的研究进展,探讨了铁基非晶合金的结构和性能与非晶合金的成分以及辐照粒子的类型、能量、注量之间的关系,以及辐照晶化的机制,为进一步促进高性能铁基非晶合金的研究提供了有价值的参考.     

Fe基非晶软磁合金的纳米晶化及磁性

研究了Fe78Si9B13,Fe73.5Cu1Nb3Si13.5B9,Fe74Cu1Mo2Nb1Si13B9三种非晶软磁合金在753～853K温度间等温退火1h后的纳米晶化行为和磁性,实验证明Cu,Nb和Mo元素的加入有助于提高晶化温度,稳定非晶组织.同时采用差热分析和X衍射仪分析了三种合金的晶化相,测量了其磁滞回线,结果表明1#,2#,3#合金分别在753K,813K,753K退火1h后可获得优良的综合软磁性能.     

Tailoring soft magnetic properties of Fe-based amorphous alloys through C addition

It is known that developing Fe-based amorphous alloys with the saturation flux density(B_s) higher than 1.65 T is a major challenge.In present work,effects of C addition on magnetic properties of Fe-based amorphous alloys were systematically studied.It has been found that the addition of C can significantly increase the saturation flux density(B_s) and the magnetic flux density at 800 A/m(B_(800)) of the Fe-B-C-Si-P amorphous alloys.After the addition of C,the B_s of the amorphous alloys increase from 1.61 T(Fe_(83)B_(13)Si_3 P_1) to 1.65-1.71 T(Fe_(83)B_(13-x)C_xSi_3 P_1,x=1.5,2,3 and 4). The Fe_(83)B_(10)C_3 Si_3 P_1 amorphous alloy possesses excellent soft magnetic properties with high B_s of 1.71 T and low H_c of 1.5 A/m.It shows that density increase of the alloys and weakened metalloid-sp/metal-d bonding caused by C addition contribute to the increment of B_s.It suggests that the newly developed high-performance amorphous alloys possess great potential in application.     

铁基非晶复合材料的磁学性能研究

采用水冷铜坩埚磁悬浮熔炼和负压铜模吸铸法,制备了Fe-15Mn-5Si-xCr-0.2C(wt.%)非晶复合材料,由XRD表征试样的物相组成,采用VSM结合M-H曲线和B-H曲线分析Cr元素含量变化对非晶复合材料磁学性能的影响.结果表明:Fe-15Mn-5Si-xCr-0.2C(x=1、2、4、6、8、10、12、13、14)试样由α-Fe相、γ-Fe相和非晶相三部分组成.Cr元素含量的增加使得合金混合焓减小而混合熵增加,Fe-15Mn-5Si-14Cr-0.2C试样中非晶相和α-Fe相的协同作用,使得试样的软磁性能最优,其矫顽力和饱和磁感应强度分别达到为16.12 A/m、5.1 T.     

Fe系非晶合金的微观结构特征研究

用差示扫描量热法（DSC），研究了Fe基非晶合金在不同的升温速率（5K／min、10K／min、20K／min、40K／min）下的DSC曲线，通过观察其不同的差热曲线，得到晶化放热峰和晶化吸热峰的位置，同时阐述了X射线衍射强度与径向分布函数（RDF）之间的关系、衍射强度的实验测定，并且结合计算非晶态合金径向分布函数的基本原理，计算了Fe基非晶合金的RDF。计算结果表明，在非晶态材料中随着与选作原点的原子间距离的增加，相关性就迅速减弱，在相距几个原子间距的原子之间就显不出相关作用，其相对位置接近完全无序。从而，由实验结果计算获得Fe系非晶合金的微观结构参数：最近邻原子间距R1=2．63712，次近邻原子间距R3=4．94952，配位数CN=12．83063。     

Mechanical behaviors of extruded Mg alloys with high Gd and Nd content

The influence of alloying elements and heat treatment on the microstructure and mechanical behaviors of extruded Mg–Gd–Nd ternary alloys was investigated in this study. The grain sizes dramatically decreased after extrusion, and the particles which distributed in Mg matrix had great effect on the grain size. The grain sizes of extruded alloys decreased from 26 to 5 μm with the alloying content increasing. The mechanical test results show that both Gd and Nd had positive effect on the hardness, y...     

非晶的激波晶化与高压变态对比研究

研究了非晶合金Ｆｅ７８Ｂ１３Ｓｉ９ 、（Ｆｅ０９９ Ｍｏ００１）７８Ｂ１３Ｓｉ９ 的激波晶化特点． 用Ｃｌｕｓｔｅｒ 模型讨论了在激波作用下晶化相的形成, 并把激波晶化与非晶高压变态作了比较． 为了更好地理解激波与非晶合金的相互作用, 还需要更进一步的实验工作和理论研究     

Formation and properties of high Fe-content Fe-(B-Si)-Zr bulk amorphous alloys

The present work is devoted to the development of Fe-(B-Si)-Zr amorphous alloys with high glass-forming ability and good magnetic properties. Using the cluster-plus-glue-atom model proposed for ideal amorphous structures, [FeFe₁₁B₃Si](Fe_1?xZr_x) was determined as the cluster formula of Fe-(B-Si)-Zr alloys. The glass formation and thermal stability of the serial alloys, namely, [FeFe₁₁B₃Si](Fe_1?xZr_x) (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.75, and 1.0), were studied by the combination of copper mold casting, X-ray diffraction, and differential thermal analysis techniques. The maxima of glass-forming ability and thermal stability were found to occur at the compositions of [FeFe₁₁B₃Si](Fe_0.6Zr_0.4) and [FeFe₁₁B₃Si](Fe_0.5Zr_0.5). The alloys can be cast into amorphous rods with 1.5 mm diameter, and upon reheating, the amorphous alloys exhibit a large undercooled liquid span of 37 K. The saturation magnetization of the [FeFe₁₁B₃Si](Fe_0.5Zr_0.5) amorphous alloy was measured to be 1.4 T.     

Phase stability in high entropy alloys: Formation of solid-solution phase or amorphous phase

The alloy design for equiatomic multi-component alloys was rationalized by statistically analyzing the atomic size difference, mixing enthalpy, mixing entropy, electronegativity, valence electron concentration among constituent elements in solid solutions forming high entropy alloys and amorphous alloys. Solid solution phases form and only form when the requirements of the atomic size difference, mixing enthalpy and mixing entropy are all met. The most significant difference between the solid solution forming high entropy alloys and bulk metallic glasses lies in the atomic size differen ce. These rules provide valuable guidance for the future development of high entropy alloys and bulk metallic glasses.     

Phase stability in high entropy alloys: Formation of solid-solution phase or amorphous phase

The alloy design for equiatomic multi-component alloys was rationalized by statistically analyzing the atomic size difference, mixing enthalpy, mixing entropy, electronegativity, valence electron concentration among constituent elements in solid solutions forming high entropy alloys and amorphous alloys. Solid solution phases form and only form when the requirements of the atomic size difference, mixing enthalpy and mixing entropy are all met. The most significant difference between the solid solution forming high entropy alloys and bulk metallic glasses lies in the atomic size difference. These rules provide valuable guidance for the future development of high entropy alloys and bulk metallic glasses.     

非晶AlNiZr合金成分的优化

为了解决铝基非晶合金在形成过程中容易析出α-Al晶体导致玻璃形成能力较低且不易评估的问题,设计了简单易行的玻璃形成能力评估方法,对非晶AlNiZr合金成分进行优化.首先,制备9种不同组分的AlNiZr合金铸锭;然后,在相同制备条件下,用单辊甩带法制备不同组分的合金薄带;最后,采用X射线衍射仪对薄带进行XRD表征,基于X...     

块体非晶合金的研究进展

块体非晶合金具有比各种传统材料更为优异的物理、化学、力学性能及精密成型性,因而一直是材料科学与物理研究的热点。本文分析讨论了该领域中存在的一些基本的问题,并从成分结构条件、热力学条件、动力学条件等方面阐述了块体非晶合金的形成机制,介绍了块体非晶合金优异的性能和应用前景,并扼要介绍了块体非晶合金未来的发展趋势及方向。     

锻态粉末冶金铁基合金的显微组织和力学性能

采用金相观察、能谱分析、X线衍射和洛氏硬度测定等研究锻态粉末冶金铁基合金显微组织和力学性能演变的规律。研究结果表明:锻造态铁基合金已经开始发生再结晶,但再结晶晶核较少,再结晶不完全,晶界处有第二相析出,析出相成分主要为Ti,Y和O;经1300~1450℃热处理后发生了再结晶,在1300℃再结晶完全,晶粒细小,第二相弥散分布于晶粒内部,样品最高洛氏硬度达54.8;随着热处理温度的提高,晶粒长大明显,强化相颗粒长大,导致洛氏硬度下降;经700℃退火后,铁基合金材料晶粒尺寸变化不明显,X线衍射峰向右发生偏移,Cr的固溶度降低,洛氏硬度下降明显。     

低居里点FeCrB非晶合金的磁热效应

基于输电线路抗覆冰的应用背景,通过对Fe100-x-yCrsBy（x=11～20,y=9-20）的成分调节和快淬工艺参数控制,制备了同时具有低居里温度和高饱和磁极化强度的非晶带材．测试研究表明Fe65Cr15B20和Fe64Cr16B20的居里温度分别为28．6和11．6℃,Fe65Cr15B20和Fe64cr16B20在0℃的饱和磁极化强度分别为0．69和0．62T．设计组装了一种近似绝热磁致热功率的测量装置,用该装置对Fe65cr15B20和Fe64cr16B20两种非晶合金带的磁热功率进行了近似测量和分析．     

Fe-Al-Nd三元合金非晶形成成分范围的理论预测

用作者提出的基于晶态固溶体的自由能和相应的非晶态的过剩自由能比较定量预测三元合金形成非晶成分范围的方法,对Fe-Al-Nd三元合金系形成非晶的成分范围进行了计算,其理论预测的形成非晶的成分范围与已有的实验结果相符。     

高铌高磷GH4169 C和GH4169合金的组织稳定性

为研究高铌高磷GH4169C高温合金在高温长期时效过程中的组织稳定性,通过场发射扫描电镜和数显布氏硬度计对GH4169和GH4169C两合金分别经600、650、704及720℃时效30~10000 h的显微组织和硬度变化进行对比分析。结果表明：在服役温度(650℃)范围内长期时效,GH4169合金和GH4169C合金均表现优异的稳定性;在服役温度以上长期时效, GH4169合金和GH4169C合金稳定性较差,短时间内,合金组织就出现失稳。对比而言,704℃时GH4169C合金组织稳定性较GH4169合金高,而720℃时GH4169C合金组织稳定性劣于GH4169合金。分析认为,GH4169C合金由于提高Nb含量和P含量使的γ＇相稳定性增加,得以在服役温度以上(704℃)表现比GH4169合金更为优异的组织稳定性,但Nb含量的提高也引起啄相含量的增加,导致组织稳定性下降。在超高温(720℃)下,GH4169C 合金稳定性劣于 GH4169合金。由此推知,相比GH4169合金,改型GH4169C合金在使用温度上有所提高,但提高有限,在超高温下,其稳定性反而降低。     

Fe基涂层切削振动特性分析研究

切削振动会对涂层结合强度产生一定的影响,强烈地振动甚至会导致涂层的脱落。在不同主轴转速下,通过对Fe基涂层加工过程中的振动进行测量,并与基体材料45钢进行对比,分析了Fe基非晶涂层切削加工过程中的振动特性。结果表明:45钢在切削过程中的振动只包含自激振动;Fe基涂层切削过程中的振动包含自激振动和强迫振动,且主轴转速越高,切削力越大,涂层受迫力随之增大,Fe基涂层切削加工振动加速度幅值越大。     

铁粉表面硫化处理制备高密度Fe-Cu-C合金

突破常规铁基粉末合金的制备工艺,设计出一种制备高密度Fe-Cu-C合金的新工艺.通过对铁粉表面进行硫化处理,Fe与S反应合成FeS,均匀包覆在Fe粉颗粒表面,形成一层FeS润滑薄膜,有利于降低压制摩擦力.通过X射线衍射、扫描电镜、和场发射扫描电镜分析研究材料的物相、元素分布和显微组织.研究结果表明:包覆在铁粉颗粒表面的FeS薄膜,有利于提高压坯密度,活化烧结.当S质量分数为0.5%时,硫化处理的Fe-2Cu-0.8C合金的力学性能优异,压坯密度7.31 g·cm-3,硬度78.6 HRB,抗拉强度485 MPa;当S质量分数达到0.8%时,多余的FeS占压制体积分数,导致试样的压坯密度降低,力学性能降低.     

非晶态Fe-Zr-B-Dy合金的制备与磁热性能

非晶态磁热合金材料可以在很宽的温度范围内实现较大的磁制冷容量,其中铁基非晶态磁热合金因其具有近室温的磁熵变区间和低廉的成本受到广泛关注.本文通过感应熔炼铜辊甩带的方法成功制备出了一系列Fe_89?xZr₇B₄Dy_x(x=1,2,3,4)非晶态合金,并对其非晶形成能力和磁热性能进行了系统测试和分析.随着Dy含量的增加,该合金的玻璃形成能力得到改善,居里温度从296 K增加到334 K.磁熵变峰值和制冷能力也随着Dy含量的增加单调增长,在3 T的外加磁场下,Fe85Zr7B4Dy4合金的最大磁熵变达到了2.45 J K^?1 kg^?1,制冷能力为235 J kg^?1,相对于三元Fe-Zr-B体系,同一磁场下的磁熵变峰值提高60%以上.该非晶态合金原材料成本低廉,其磁热性能随着成分变化可以调控,居里温度远低于玻璃转变温度,能够保证材料在使用过程中的结构稳定性,有成为近室温的磁制冷工质的潜力.