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1.
张东彬  吴承建 《金属学报》1988,24(2):100-105
用TEM+EDAX和AES方法研究了Fe-0.3%P-0.16%Ce和Fe-0.3%P合金Ce和P的晶界平衡偏聚及Ce对P平衡偏聚的影响,并且对合金的脆性做了研究.结果表明,Fe-0.3%P-0.16%Ce合金晶界有Ce和P的共偏聚,磷的平衡偏聚量不低于Fe-0.3%P合金,但是脆性却由于Ce的偏聚而显著改善.本文从界面二维相的观点讨论了Ce和P在晶界的相互作用.  相似文献   

2.
提出了用TEM+EDX技术分析溶质在晶界的偏聚所必需的近似处理方法。用该技术分析了Fe-0.3%P-0.16%Ce合金中铈和磷的晶界偏聚,并将结果与AES在同一合金中的结果进行比较。结果表明,TEM+EDX结合所提出的近似处理方法研究溶质的晶界偏聚现象是可行的。在Fe-0.3%P-0.16%Ce合金中测得铈和磷在晶界上有较高浓度的共偏聚。本文还研究了铈在α-Fe晶界平衡偏聚的规律。  相似文献   

3.
利用硼径迹显微照相(PTA)技术研究了体心立方Fe—3%Si合金试样在冷却和淬火等温过程中硼向晶界的偏聚行为结果表明:Fe-3%Si合金中硼的晶界平衡偏聚趋势高于奥氏体合金,也不存在淬火诱导硼向晶界的非平衡偏聚.硼原子与晶界结合能Q=55.7 kJ/mol用淬火诱导非平衡偏聚的复合体机制解释了硼在Fe-3%Si合金与奥氏体合金中偏聚行为异同的原因.  相似文献   

4.
林文松 《热处理》2004,19(2):18-21
溶质元素在金属晶界的偏聚可以分为两类,即平衡偏聚和非平衡偏聚。本文回顾了这两类偏聚现象及其机理,着重讨论分析了有重要工程用途的三类典型的晶界偏聚:硼在奥氏体晶界的两类偏聚的实验规律及对硼钢淬透性影响;磷在奥氏体晶界的平衡偏聚及对钢回火脆性的作用,钢中的其他合金元素对磷的偏聚的影响;硼在多种金属间化合物的偏聚及对这些金属间化合物塑性的影响及其机理。  相似文献   

5.
硼在奥氏体晶界的两类偏聚   总被引:8,自引:0,他引:8  
用PTA法研究了Fe-30%Nj合金中硼在晶界的偏聚行为.实验表明,在550—1200℃保温后,用不同方式冷却的试样中存在有平衡与非平衡两类硼偏聚,其形成机制各不相同,而且试验条件的影响亦不同.保温时形成的平衡偏聚在低温淬火试样中起主要作用.在高温加热后,用通常冷速冷却时,晶界偏聚主要来源于冷却过程中产生的非平衡偏聚.实际试样中观察到的硼偏聚是这两类偏聚的叠加,主要偏聚方式的转折温度区受冷却速度影响,在中等冷速下,这个转折温度在650—750℃之间。  相似文献   

6.
在 1 0 2 3~ 1 373K的初始温度和 4 48K s及 2 69 91K s的冷速下 ,用俄歇剖层分析确定含硼和钙的Ni3 Al合金中钙的平衡晶界偏聚和含硼和硅的Ni3 Al合金中硅的平衡晶界反偏聚行为。按照多组元平衡偏聚理论对实验结果进行了描述和分析 ,并确定出钙的平衡晶界偏聚自由能和硅的平衡晶界反偏聚自由能。实验证实在Ni3 Al B Ca合金中存在钙和硼的平衡晶界共偏聚 ,而在Ni3 Al B Si合金中存在硅对硼平衡晶界偏聚的促进作用  相似文献   

7.
Fe—P与Fe—P—Ce合金中的晶界磷偏聚及其对脆性的影响   总被引:9,自引:0,他引:9  
用XPS,AES及系列冲击试验等方法对含磷0.032—0.22wt%的Fe-P和Fe-P-Ce合金中晶界偏聚磷的存在状态、偏聚特点及对脆性的影响进行了研究。结果表明,晶界上磷的存在状态与其偏聚量有关。当偏聚量较低时,为固溶态,且Ce的影响很小,而当偏聚量较高时,其存在状态改变,且Ce的影响显著。  相似文献   

8.
晶界元素偏聚及其机理的研究进展   总被引:2,自引:0,他引:2  
晶界成分偏聚对多晶材料的力学性能有很大影响,探明影响晶界成分偏聚的因素和偏聚机理,对改善材料性能和优化设计合金系统具有重要意义。本文通过归纳近几年来国内外原子尺度研究晶界成分偏聚及其机理的研究进展,分析了间隙原子,置换型原子和空位在晶界的偏聚及其对材料性能的影响,讨论了成分偏聚与合金元素择优占位行为的关系,总结了晶界成分偏聚对材料力学性能影响的根本原因。  相似文献   

9.
高温合金GH4169(Inconel 718)中磷晶界偏聚特性的实验研究   总被引:1,自引:0,他引:1  
郑磊  徐庭栋  邓群  司红  董建新 《金属学报》2007,43(8):893-896
采用Auger电子能谱仪测量了镍基高温合金GH4169中磷(P)的晶界偏聚量.结果表明,经1020与1200 ℃固溶处理后在720 ℃时效2 h的样品,P的晶界偏聚浓度分别是0.344%与0.412%(原子分数).晶界偏聚浓度随固溶处理温度的升高而升高.基于这一实验结果,确定了P在该合金中的非平衡晶界偏聚特性.  相似文献   

10.
应用扫描俄歇探针研究了硼在金属间化合物Ni3Al晶界的平衡偏聚特性。研究结果表明,硼在Ni3Al晶界的偏聚符合Langrnuir一McLean平衡偏聚理论;实验得到硼在Ni-24at.-%Al合金中晶界偏聚自由能△G=-22159-24.74T(J/mol):硼在Ni3Al晶界的偏聚受晶界结构和晶界化学环境的影响。不同结构的晶界存在着硼偏聚的不均匀性,硼在富镍晶界的偏聚比在富Al晶界更为显著,合金元素对硼在Ni3Al晶界偏聚的影响与其在Ni3Al中占据的亚阵位置有关。  相似文献   

11.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

12.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

13.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

14.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

15.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

16.
Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.  相似文献   

17.
正Harbin General Hydraulic Machinery Works Co.,Ltd.of Yilin Hydraulic Group is the most professional production base of large-scale metallurgy oil cylinder and oil machinery cylinder in the Northeast of China.The main products include metallurgy cylinder,swell-shrink cylinder,rotating injection device,lifting cylinder,main lifting jack,front lifting jack,engineering oil cyl-  相似文献   

18.
<正>Copyright Information For Authors As soon as an article is accepted for publication,authors will be requested to assign copyright of the article(or to grant exclusive publication and dissemination rights)to the publisher(respective the owner if other than Springer).This will ensure the widest possible protection and dissemination of information under copyright laws.More information about copyright regulations for this journal is available at  相似文献   

19.
《中国铸造》2014,(6):539-539
The ANKIROS/ANNOFER/TURKCAST shows held on Sept. 11-14, 2014, in Istanbul, Turkey, provided an ideal opportunity for the World Foundry Organization Executive Board to meet and discuss member benefits. Nine executive board members attended the meeting, including Dr. Lou Yanchun, Vice President of FICMES and President of Shenyang Research Institute of Foundry. During the board meeting, the WFO executives agreed to establish a special working group which is responsible for drafting a strategical plan for the WFO and submitting it for discussion at the next board meeting in 2015.  相似文献   

20.
《中国铸造》2014,(5):460-463
The 9th China International Diecasting Congress and the 1st International Symposium on Nonferrous Alloys and Special Casting Technologies (ISNASCT) were successfully held in Shanghai on July 19-22, 2014. Both events were jointly sponsored by Chinese Mechanical Engineering Society, Die Casting Commission of World Foundry Organization and Non-Ferrous Materials Commission of World Foundry Organization, and organized by the Foundry Institution of Chinese Mechanical Engineering Society (FICMES) and China Productivity Promotion Center of Foundry Industry.  相似文献   

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