机械合金化形成的Fe—Cu纳米晶过饱和固溶体的硬化及软化

用机械合金化方法，在不互溶的Ｆｅ－Ｃｕ二元系的富Ｆｅ端和富Ｆｅ端和Ｃｕ端，分别制备出ｂｃｃ和ｆｃｃ结构的纳米晶过饱和固溶体，用Ｘ射线衍射和显微硬度分析等方法，系统研究了晶粒尺寸，溶质原子含量等因素对Ｆｅ－Ｃｕ纳米晶过饱和固溶体硬度的影响。结果表明，在富Ｃｕ端形成的ｆｃｃ纳米晶过饱和固溶体的硬度、随溶质原子Ｆｅ含量的增加而升高，而在富Ｆｅ端形成的ｂｃｃ纳米晶过饱和固溶体的硬度，随溶质原子Ｃｕ量的增加     

难互溶Cu—Fe系机械合金化的高分辨电镜研究

机械合金化可使室温下几乎不互溶体系Ｃｕｘ－Ｆｅ（１００－ｘ）形成过饱和固溶体。ｆｃｃ相区的固溶度范围扩展到ｘ＞３５ａｔ．－％．对Ｃｕ４０Ｆｅ６０进行的高分辨电镜观察表明：球磨３ｈ后ｂｃｃ相与ｆｃｃ相之间存在Ｎ－Ｗ关系，即＜００１＞α∥＜１１０＞γ∥＜１１０＞α∥＜１１１＞γ表明在球磨的过程中发生了逆马氏体相变，ｆｃｃ相区的扩展与此密切相关，球磨６０ｈ后形成了尺寸比较均匀的钠米晶结构，高分辨电镜同时     

铜对铁基微晶合金组织和性能的影响

本文综述了新型含Ｃｕ铁基超微晶合金的软磁性能，重点阐述了Ｃｕ对高性能铁基纳米微晶及高饱和磁感铁基微晶会金软磁性能的改善及对其ｂｃｃ相晶粒的形核及细化作用。由于Ｃｕ在铁基合金中具有偏析的倾向，使含Ｃｕ铁基非晶合金在晶化温度以上热处理时形成细小而稳定的α－Ｆｅ晶体。Ｃｕ的加入使铁基微晶合金的ｂｃｃ相区的温度范围扩大，并将化合物的形成温度推向高温区，因而在宽的温度范围内退火后的含Ｃｕ铁基微晶会金能得到单一而细小的α－Ｆｅ晶粒组织，而细小α－Ｆｅ的组织是获得优异软磁性能的有效途径。     

碳钢表面热压复合Al70Cu8Fe10Cr12准晶合金梯度支的组织与性能

采用热压技术把Ａｌ７０ＣｕＦｅ１０Ｃｒ１２准晶合金粉与碳钢复合，在热压过程中准晶合金与碳钢发生扩散反应，使得在碳钢表面形成了上过渡层与合金层组成的梯度层。研究了该梯度层的组织、成分及硬度分布，发现过渡层主要由α－Ｆｅ和ＦｅＡｌ相组成。合金层从里向外由Ａｌ－Ｃｕ－Ｆｅ－Ｃｒ系复杂化合物和十次准晶相组成。整个梯度层的硬度ＨＶ由２５０到１２５０逐渐增加。     

宽滞后形状记忆合金丝试制成功

通过Ｍｎ的加入量的变化，探讨了Ｍｎ在Ｗ－Ｎｉ－Ｆｅ－Ｃｏ（Ｍｎ）系重合金中的存在状态及其作用机制。结果表明：Ｍｎ的存在，可使Ｗ－Ｎｉ－Ｆｅ－Ｃｏ系重合金的塑性和韧性得以提高；Ｍｎ在合金中，主要以球形细小颗粒状ｆｃｃ的ＭｎＯ的Ｍｎ３Ｏ４四方晶系的Ｍｎ２Ｏ３，正交、四方及ｂｃｃ的Ｍｎ２Ｏ３，正交晶系的ＭｎＯ２及ｒ－ＭｎＯ２，六角晶系的δ－ＭｎＯ２和ｆｃｃ的ａ－ＭｎＳ之状态弥散分布于粘结相中，且部分固溶     

四元扩散偶技术及其在相图研究中的应用（Ⅱ）Mo－Fe－Ni和Mo－Ni－Co三元系在1200℃时的相平衡

采用一个Ｍｏ－Ｆｅ－Ｎｉ－Ｃｏ四元扩散偶试样，测定了Ｍｏ－Ｆｅ－Ｎｉ和Ｍｏ－Ｎｉ－Ｃｏ在１２００℃时的两个三元系等温截面；并借助金相显微镜、扫描电镜能谱仪以及电子探针，确定了Ｍｏ－Ｆｅ－Ｎｉ三元系在１２００℃时三元合金中三元化合物Ｐ相的存在。该系统中存在ｂｃｃ（Ｍｏ）、μ－Ｆｅ７Ｍｏ６、δ－ＭｏＮｉ、ｂｃｃ（Ｆｅ）、ｆｃｃ和Ｐ六个单相区；在Ｍｏ－Ｎｉ－Ｃｏ三元系中存在ｂｃｃ（Ｍｏ）、δ－ＭｏＮｉ、μ－Ｃｏ７Ｍｏ６和ｆｃｃ四个单相区。     

用X射线能谱研究金基六元合金

利用Ｘ射线能谱（ＥＤＳ）和透射电子显微术（ＴＥＭ）等手段研究了Ａｕ－Ｎｉ－Ｆｅ－Ｃｒ－Ｉｎ－Ｚｒ合金的显微组织。研究结果表明，合金主要由Ａｕ基固溶体和Ｎｉ基固溶体组成。此外还有两种第二相粒子，一种粒子（命名为η相）含Ｃｒ量为９０ａｔ％，属简单正交结构，ａ＝０．４４８ｎｍ，ｂ＝１．４０ｎｍ，ｃ＝１．２１ｎｍ；另一种粒子为具有ｆｃｃ结构的化合物（Ｎｉ，Ａｕ）＿５Ｚｒ，ａ＝０．６８２ｎｍ。     

Fe85Zr9B6和Fe84Zr9B6Cu1非晶合金形成纳米晶的机制

本文利用透射电子显微学和能谱分析技术研究了ＦｅＺｒＢ（Ｃｕ）非晶合金在动态升温过程中和不同热处理温度下微观结构的变化。研究发现，在合金晶化过程中，非晶相由富Ｚｒ和富Ｆｅ区组成。富Ｚｒ相对ｂｃｃ Ｆｅ相的析出和稳定性有着重要的影响。α－Ｚｒ相的析出是ｂｃｃ Ｆｅ相开始失稳长大的标志。     

FORMATION MECHANISM FOR NANOCRYSTALLINE FROM AMORPHOUS Fe_（85）Zr_9B_6 AND Fe_（84）Zr_9B_6Cu_1 ALLOYS

本文利用透射电子显微学和能谱分析技术研究了ＦｅＺｒＢ（Ｃｕ）非晶合金在动态升温过程中和不同热处理温度下微观结构的变化．研究发现，在合金晶化过程中，非晶相由富Ｚｒ和富Ｆｅ区组成．富Ｚｒ相对ｂｃｃＦｅ相的析出和稳定性有着重要的影响．α－Ｚｒ相的析出是ｂｃｃＦｅ相开始失稳长大的标志．     

快速凝固Al－Fe－Ti－C合金的显微结构及退火过程中的相变SCIEI

研究了快速凝固Ａｌ－Ｆｅ－Ｔｉ－Ｃ合金的显微结构及退火过程中的相变。初始快凝态组织由α－Ａｌ微胞晶组成，在胞晶边界分布着较大并拉长的非晶相；在胞晶内部则为细小弥散的球状亚稳Ａｌ_６Ｒｅ相（底心正交结构），Ｔｉ和Ｃ全部过饱和固溶于α－Ａｌ中。当７７３Ｋ退火５ｈ时，非晶相转变为α_Ｔ－ＡｌＦｅＳｉ相（斜方结构），Ａｌ_６Ｆｅ相部分转变为片状Ａｌ_３Ｆｅ相（底心单斜结构），部分长大但仍保持球状和底心正方结构过饱和固溶于α－Ａｌ基体中的Ｔｉ和Ｃ则以ＴｉＣ形式弥散析出。     

Effect of High Configuration Entropy and Rare Earth Addition on Boride Precipitation and Mechanical Properties of Multi-principal-Element Alloys

A series of multi-principal-element (MPE) alloys have been prepared by adding Ni, Mn, Al, Cu and Y into the reference CoCrFe-B alloy. The microstructure and mechanical properties of these MPE alloys have been investigated thoroughly. It is found that the addition of the elements can inhibit boride precipitation in the designed alloys and the solid solution strengthening effect induced by interstitial boron atoms is more significant than that by boride precipitation. The MPE alloys with the fcc phase as the main solid solution phase have a higher boron solubility and hence less boride precipitation, than those with the bcc phase as the main solid solution phase. The addition of yttrium can improve the boron solubility, decrease boride precipitation, control the boride morphology and, importantly, simultaneously improve the compressive strength and ductility of boron-containing MPE alloys.     

含B量对激光熔覆FeCoCrNiB_x(x=0.5,0.75,1.0,1.25)高熵合金涂层组织结构与耐磨性的影响

采用激光熔覆技术制备FeCoCrNiBx高熵合金涂层,用X射线衍射(XRD)、扫描电镜(SEM)、硬度和耐磨测试等方法,研究了B含量对激光熔覆FeCoCrNiBx高熵合金涂层的组织结构、硬度和耐磨性能的影响。结果表明,随B含量的增加,合金相结构逐渐由fcc固溶体结构转变为fcc固溶体和M3B相共存,M3B相主要为Cr、Fe硼化物。随B含量的增加,枝晶组织中析出颗粒状和短棒状的M3B相,且M3B相逐渐长大成长条状。B的增加显著提高合金涂层的硬度,由4470 MPa增加到8480 MPa,且磨损量随着B的增加而减少。     

亚稳态Fe-Cu固溶体合金的(Ms-电子/原子)曲线

用机械合金化(MA)锻压方法制备了bcc和fee结构的块状亚稳态Fe-Cu固溶体系统,并对系统的磁化强度、价电子结构进行了测量和计算,从亚稳态Fe-Cu固溶体的饱和磁化强度Ms-e／a(电子／原子)曲线可看出：大约在26．2e／a的区域Ms有最大值,并且在大约28．6e／a的区域接近零．这个结果与Fe-Co和Fe-Ni系统类似(在大约26．2e／a的区域Ms最大,在大约28．6e／a时Ms近似为零).由此我们推论：相对在0K亚稳态Fe-Cu固溶体的每原子的电子数字的饱和磁矩(Ms)曲线与其它二元过渡金属(Fe-Co和Fe-Ni)的曲线类似．在Cu含量大约为35mol％(此时平均电子结构为27．1e／a)时的混合相区域出现负的曲率．     

Effect of Sn on synthesis of nanocrystalline Ti-based alloy with fcc structure

The effect of the amount of Sn on the formation of fcc phase in Ti−13Ta−xSn (x=3, 6, 9 and 12, at.%) alloys was studied. The alloys were synthesized by mechanical alloying using a planetary mill, jar and balls of stabilized yttrium. Using Rietveld refinement, it was found that the obtained fcc phase has crystallite size smaller than 10 nm and microstrain larger than 10⁻³. Both conditions are required to form an fcc phase in Ti-based alloys. For all samples, the microstructure of the fcc phase consists of equiaxial crystallites with sizes smaller than 10 nm. The largest presence of fcc phase in the studied Ti alloy was found with 6 at.% Sn, because this alloy exhibits the largest microstrain (1.5×10⁻²) and crystallite size of 6.5 nm. Experimental data reveal that a solid solution and an amorphous phase were formed during milling. The necessary conditions to promote the formation of solid solution and amorphous phases were determined using thermodynamic calculations. When the amount of Sn increases, the energy required to form an amorphous phase varies from approximately 10 to approximately −5 kJ/mol for 3 and 12 at.% Sn, respectively. The thermodynamic calculations are in agreement with XRD patterns analysis and HRTEM results.     

Fe-Cu二元合金中的B2析出相及时效硬化(英文)

研究了不同成分的Fe-Cu二元合金在过饱和固溶体状态下晶粒尺寸和硬度之间的关系,分析了Cu元素的固溶强化作用。研究了Fe-Cu二元合金的时效硬化现象和Cu元素的析出过程。结果表明Fe-Cu二元合金硬度值增加近一倍。通过透射电镜观察到随时效时间的增加,析出相的尺寸逐渐增大,形状由球形变为棒状。电子衍射花样分析得知,时效处理硬度达到最大值时对应的析出相具有B2型晶体结构,与基体之间保持平行位向关系。透射电镜观察到位错与析出相之间存在典型的引力型交互作用,由于软析出相对运动位错的钉扎效应而使Fe-Cu二元合金得到有效强化。     

B含量对FeCrCoNiMn高熵合金组织及力学性能的影响

采用真空电弧熔炼炉制备了FeCrCoNiMnBx高熵合金,并对其微观组织和力学性能进行测试。未加入B元素时,合金组织具有单一FCC结构的胞状晶。B含量≥0.05时(at%),组织由FCC结构和具有树枝状和纳米颗粒状(Cr,Fe)₂B组成。随B含量的增加,合金的抗拉强度逐渐增加,硼含量为0.2(at%)时,合金的抗拉强度达到最大值610 MPa,但延伸率只有7%。B含量为0.1时,合金的综合力学性能最佳,抗拉强度为550MPa,延伸率为20%。故加入适量的B元素能提高高熵合金综合力学性能。     

Matrix Transformation in Boron Containing High-Temperature Co–Re–Cr Alloys

An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr₂Re₃ type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content.     

Structural state of Ni-Mn solid solutions in a wide range of concentrations based on the data of scattering and absorption of X-rays

It has been demonstrated that Ni-Mn alloys prepared from elemental powders by the method of mechanical alloying appear to be fcc solid solutions in a wide concentration range. Structural studies of samples with the amount of Ni from 50 to 95 at % were carried out by the methods of X-ray diffraction, electron microscopy, and EXAFS spectroscopy.     

快淬工艺对La-Mg-Ni系贮氢合金微观结构及电化学性能的影响

用铸造及快淬工艺制备了La-Mg-Ni系（PuNi3型）贮氢合金La2Mg（Ni0．85Co0.15）9Bx（x=0，0．1，0．2），分析测试了铸态及快淬态合金的微观结构与电化学性能，研究了硼及快淬工艺对合金微观结构及电化学性能的影响。结果表明，铸态合金具有多相结构，主相包括（La，Mg）Ni3相（PuNi3型）和LaNi5相，残余相为一定量的LaNi2相和微量的Ni2B相，经快淬处理后Ni2B相消失，并且其它相的相对量随淬速的变化而变化。不含硼合金的容量随淬速的增加而单调减小，含硼合金的容量随淬速变化有一个极大值。合金的循环寿命随淬速的增加而增加，铸态及快淬态合金均有优良的活化性能。