TbCu7型SmCo7-xHfx合金的结构及磁性能

采用熔体快淬法在40 m/s制备了SmCo_7-xHf_x （x=0, 0.1, 0.15, 0.2, 0.3）合金薄带,研究Hf取代量对SmCo_7-xHf_x合金的相组成、组织结构及磁性能的影响.结果表明:随Hf取代量的增加,均可获得TbCu₇型结构的亚稳相,晶格常数a和c也随之增加,c/a比值在0.82~0.83,晶粒平均尺寸减小,且更加均匀;在性能方面,Hf取代量为0.2时,可获得最优磁性能B_r为0.55 T和H_c为1 084 kA/m. Hf的添加还可有效改善合金高温性能,在27~400 ℃温度区间,矫顽力温度系数由未添加时-0.21 %/℃改善到-0.18 %/℃,提升14.3%.      

铸造FeCrCo合金显微结构和磁性能研究

主要研究了热处理对FeCrCo合金的磁性能和微观组织的影响。结果表明，合金经固溶化处理后保证基体是单相α，然后再进行磁场处理和多级回火获得最佳的调幅分解组织。     

Tb对Fe81Ga19快淬合金薄带组织和磁致伸缩性能的影响

利用快淬甩带方法制备了Fe81Ga19Tbx(x=0,0.2,0.4,0.6)合金薄带,研究了合金薄带的显微组织结构和磁致伸缩性能。实验结果表明,Fe-Ga-Tb合金薄带的显微组织及磁致伸缩性能与合金的成分密切相关,合金薄带基体为Fe(Ga)无序固溶相体。Fe81Ga19Tb0.2合金的磁致伸缩系数最大,达到-1320×10-6,且薄带厚度方向[100]择优取向,Tb在晶界处富集。     

高碳铬铁合金固相显微结构及破碎性能

为了研究高碳铬铁合金在浇注过程添加硅铁粉和铝后固相显微结构及破碎性能变化,在0.2 t多功能炼钢中试炉重熔某铁合金公司生产的高碳铬铁,浇注时分别添加硅铁粉和铝,分析重熔的常规高碳铬铁、添加铝及硅铁粉的高碳铬铁的固相显微结构,并将样品经颚式破碎机破碎。结果表明,高碳铬铁显微结构主要由(Cr,Fe)7C3固态相和(Cr,Fe)7Si固态相组成,有部分TiN、MnS和Al2O3夹杂物析出,常规高碳铬铁中未发现Al2O3夹杂物,而添加硅铁粉和铝的高碳铬铁中均析出了Al2O3及TiN夹杂物;添加铝的高碳铬铁组织致密,气孔率小,而常规高碳铬铁存在大量裂纹和孔洞,组织疏松,添加硅铁粉的高碳铬铁介于两者之间;经颚式破碎机破碎后,常规高碳铬铁、添加硅铁粉的高碳铬铁和添加铝的高碳铬铁破碎后粉末率分别为13.2%、11.7%和9.5%。     

借助腐蚀技术研究Ni42合金薄带的应力分布

借助腐蚀技术，研究了合金薄带的应力分布，根据腐蚀试样的翘曲程度，可判定材料内应力的大小。实验结果表明：应力沿轧制方向分布大，而横向分布小，并得出在厚度方向分布的规律。同时阐明了经张力退火后，使沿轧制方向分布的应力基本消失，而剩余的极小量的应力，也改变了原来的分布规律。文中还进一步探索了在加工过程中与应力有关的因素，从而有效地把应力控制在与国外同类产品的应力范围之内，提高了产品的合格率。     

稀土对Cu—Ni—Zn合金性能及显微结构的影响

研究了稀土对ＣｕＮｉＺｎ合金机械性能及显微结构的影响。用扫描电镜、金相显微镜及Ｘ射线衍射等方法观察、分析了稀土元素在合金中的分布及作用。试验结果表明,稀土对ＣｕＮｉＺｎ合金机械性能及显微结构均有影响,主要表现在细化铸锭组织及再结晶组织,提高抗拉强度及硬度,而延伸率有所下降;但合金中的稀土添加量不能大于１０％,超过该范围时合金的热塑性变差,难以加工成形     

特种合金双辊薄带连铸生产技术进展

双辊薄带连铸技术（TRC）已发展到产业化的初级阶段,如日本新日铁、德国Eurostrip、美国Castrip、韩国Postrip等公司的薄带连铸生产能力已达30～50万t/a,多炉连浇时间超过10h。介绍了多种特种合金,如髙硅电工钢（w（Si）为4.5%～6.5%）、高速钢、Invar合金、Inconel合金、TWIP钢等可用双辊薄带连铸,一次性形成毫米级薄带。由于高速冷凝,晶粒细化,成分偏析极少,生产成本低,成材率高,TRC是当前双辊薄带连铸产业化的新途径之一。     

2 mm铁碳合金薄带固态脱碳试验

 为了探究2 mm厚的铁碳合金薄带固相脱碳规律。试验以Ar-H2-H2O为脱碳气氛,在可控气氛管式炉内对Fe-C合金薄带进行脱碳。把初始碳质量分数为4.15%和3.20%的2 mm铁碳合金薄带分别放入加热场中,然后控制不同加热温度和脱碳时间进行脱碳研究。结果表明,碳向反应界面的扩散是脱碳反应的限制性环节,脱碳温度的升高和脱碳保温时间的延长均有利于脱碳,初始碳质量分数不同的铁碳合金薄带前期脱碳速率相同。由于薄带较厚,恒温脱碳不能达到脱碳要求,从而提出了分段加热脱碳法,脱碳效果良好,初始碳质量分数为4.15%的铁碳合金薄带70 min可脱到0.28%,初始碳质量分数为3.20%的铁碳合金薄带50 min可脱到0.23%。     

锻造ZHMR4合金性能及显微结构的研究

本文采用扫描电子显微镜（SEM）、透射电镜（TEM）、能谱仪（EDS）及力学性能测试手段对ZHMR4合金的性能及显微组织进行了研究。结果表明：ZHMR4合金具有良好的加工性能，且锻造选用的工艺参数较为合理，此合金可以进行工业化生产。     

Fe-Cu-Nb-Si-B薄带的淬态纳米化与巨磁阻抗效应

使用较低的快淬速度(V =2 2m·s- 1 ) ,可以使Fe Cu Nb Si B薄带实现淬态纳米晶化。Fe Cu Nb Si B薄带析出αFe(Si)纳米相,其晶粒尺寸在淬态薄带Fe73Cu1 .5Nb3Si1 3.5B9中约为15nm ,在Fe71 .5Cu3Nb3Si1 3.5B9中约为10nm。添加Cu元素可以细化淬态薄带的晶粒。实验发现磁阻抗ΔZ/Z0 ,磁电阻ΔR/R0 ,磁电抗ΔX/X0 三条曲线交叉于一点,通过推导发现此现象具有必然性。淬态薄带Fe74 .5-xCuxNb3Si1 3.5B9的磁阻抗显示了较强的Cu含量依赖性。在快淬速度v =2 2m·s- 1 下,在x =1.5和x =3左右观察到磁阻抗峰值现象。     

Magnetic property and microstructure of SmCo magnetic recording films

Cr/SmCo/Cr thin films with Sm concentration of 37.7 at.% were deposited on glass substrates by magnetron sputtering. Meas-urement of magnetic properties showed that the SmCo film possessed good magnetic anisotropy, a high coercivity of 3019 kA/m and low magnetic exchange coupling. Microstructure analysis showed that crystallized SmCo5 magnetic phase, non-magnetic SmCo2 phase and Sm2Co7 phase co-existed ill the film. The non-magnetic SmCo2 phase might function as isolator of SmCo grains, leading to a decrease of magnetic exchange coupling. Moreover, a Cr2)3 oxide layer which could protect the SmCo layer from oxidation formed at the surface of the Cr cap layer.     

强磁场对铁基合金相变温度和显微组织的影响

The effect of a high magnetic field up to 30 T on phase transformation temperature and microstructure of Fe-based alloys has been reviewed. A high magnetic field accelerates ferrite transformation, changes the morphology of the transformed microstructures and increases the As and A1 temperature. In a magnetic field of 30 T, the A1 temperature increases by about 37.1℃ for Fe-0.8C, the A3 temperature for pure Fe increases by about 33.1 ℃. The measured transformation temperature data are not consistent with calculation results using Weiss molecular field theory. Ferrite grains are elongated and aligned along the direction of magnetic field in Fe-0.4C and Fe-0.6C alloys by ferrite transformation, but elongated and aligned structure was not found in pure Fe, Fe-0.05C alloy and Fe-1.5Mn0.11C-0.1V alloy.     

Effect of heat treatment on phase and structural transformation in SmCo5 alloy powder

Conclusions The temperature range of precipitation of the Sm₂Co₁₇ phase in a single-phase SmCo₅ powder is 600–650 °C. The formation of the Sm₂Co₁₇ phase as a result of phase separation substantially decreases the degree of texturization acquired by a powder in a magnetic field. The recrystallization temperature of SmCo₅ powder lies in the range 450–500°C.Translated from Poroshkovaya Metallurgiya, No. 7(211), pp. 70–74, July, 1980.     

射频磁控溅镀掺杂铜对钛酸锌薄膜中相变化及微结构的影响

探讨了ZnTiO₃薄膜掺杂Cu元素对于薄膜性质、相变化与微结构之影响.实验是在一定温度下以射频磁控溅镀系统将铜沉积于ZnTiO₃陶瓷靶上,控制沉积于ZnTiO₃陶瓷靶上铜含量之后,再沉积掺杂铜的钛酸锌薄膜于SiO₂/Si基板上.成长出来的薄膜经由ESCA分析得知铜的质量分数分别为0.84%、2.33%和2.84%.从XRD分析常温下掺杂Cu的ZnTiO₃薄膜为非晶质态,经过600℃退火后,ZnTiO₃薄膜则由非晶质态转变成Zn₂Ti₃O₈结晶相,而未掺杂铜的ZnTiO₃薄膜在600℃退火时并没有结晶相产生.ZnTiO₃薄膜经过900℃退火后,Zn₂Ti₃O₈相分解成Zn₂TiO₄相和TiO₂相,且ZnTiO₃晶格常数因为Cu离子置换至Zn离子的位置有变小的趋势.由TEM分析证实Cu离子与Zn离子的置换,导致晶格应变产生双晶缺陷.经由XRD、SEM和TEM分析得知掺杂太多的铜会抑制TiO₂相的生成,而随着过多的Cu析出,晶体平均晶粒慢慢变小晶格应变也随之降低,以致晶格常数回复往原来晶格常数方向趋近.     

Solidification modelling of microstructure in twin-roller thin strip casting of stainless steels

The influence of process parameters on the dendritic microstructure of thin strips cast by the twin-roll method is analyzed in the framework of a one-dimensional solidification model and compared with experimental results. As a relevant characteristic the secondary dendrite arm spacing Λ₂ as a function of the distance x from the roll surface is investigated. The difference between the local dendrite arm spacing near the strip surface and the strip centre, respectively, increases with the strip thickness and only depends on the casting temperature to a small extent. An increase in the strip/roller heat transfer coefficient due to a rising casting velocity or possibly enhanced roll-separating forces leads to a decrease in the dendrite arm spacing. The effect of a sudden decrease in heat transfer during the solidification process, on the Λ₂(x) characteristics, e.g. by a local separation of the solidified shell from the roller surface, is discussed.     

Effect of chromium interlayer on magnetic exchange coupling of SmCo/Cr/TbFeCo multilayer thin films

A series of SmCo/Cr/TbFeCo multilayer thin films with perpendicular anisotropy were prepared by RF- magnetron sputtering system, and the effects of Cr interlayer thickness on magnetic properties and interlayer exchange coupling were investigated. It was found that the magnetic properties varied with the thickness of Cr interlayer, especially the values of saturation magnetization Ms and the coercivity Hc fluctuated periodically with the thickness of Cr interlayer. STM images revealed that the variation of coercivity Hc was attributed to the microstructure change of SmCo layer influenced by Cr interlayer, and the variation of Ms was related to interlayer exchange coupling.     

Nb对高铁车轴钢相变规律及微观组织的影响

采用热力学软件Thermo-Calc、Formastor-FⅡ型全自动相变仪、OM、HRTEM等手段研究了V微合金化、Nb-V复合微合金化车轴钢的微观组织及连续冷却相变规律.结果 表明,Nb能够提高钢的Ac1和Ac3相变温度,扩大铁素体+珠光体相变区冷速范围,使贝氏体相变区向左下方移动,提高获得全马氏体的临界冷却速度....     

Effect of phase and structural transformations occurring during liquid-phase sintering on the magnetic properties of SmCo5 magnets

Conclusions A study of phase and structural transformations occurring in magnets during liquid-phase sintering has shown that the following factors have a beneficial effect on magnetic properties: single-phase structure after sintering, consisting of the compound SmCo₅ alone; presence of surface segregation zones in the grains of magnets; presence of epitaxial regions preventing magnets from growing and their texture perfection from diminishing; isolation of pores and a high relative density of magnets, which protect the latter's grains against oxidation.Translated from Poroshkovaya Metallurgiya, No. 5(185), pp. 81–87, May, 1978.     

热轧带钢层流冷却过程中温度与相变耦合预测模型

建立了温度与相变耦合有限元模型,对带钢轧后冷却过程中带钢厚度和宽度方向的温度场进行了模拟计算.建模过程中,考虑带钢的各金相组织的密度、导热系数、比热容等物性参数为温度的函数,取各相的线性平均值用于计算.根据连续等温转变实验曲线,采用Avrami方程和Scheil可加性法则计算带钢相变潜热,实现温度和相变耦合求解.计算结果表明,带钢经过层流冷却后,沿厚度方向存在着一定的温差,带钢温度沿宽度方向分布不均匀,和现场实测结果吻合.     

分段冷却对HRB400E相变过程及微观组织的影响

 HRB400E吐丝后的冷却过程决定了其微观组织组成。通过Gleeble-3500热模拟试验机模拟了HRB400E不同的冷却工艺,分析了不同冷却工艺条件下的膨胀量曲线和微观组织。试验结果表明：冷却速率和冷却速率突变温度对试验钢的最终组织组成有非常大的影响,2个参数的合理搭配,可以控制得到一定数量的贝氏体;贝氏体体积分数随突变温度的降低和冷却速率的提高呈现上升的趋势。