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1.
深过冷净化的影响因素及工艺优化   总被引:3,自引:0,他引:3  
系统地研究了熔融玻璃和循环过热相结合方法对净化效果的影响;提出了大体积液态金属获得深过冷的优化工艺;采用该工艺可快速、稳定地使6~20gNi81.15Si18.85、Ni28.64Si21.36、Ni74.17Si25.83、Ni50Cu50、Fe76B12Si12合金分别获得299K(0202Tm)、269K(o.19Tm)、263K(0.172Tm)、320K(0.202Tm)、367K(0.257Tm)大过冷,并使其保持4~6个循环周期不衰减,同时采用该工艺还首次成功地制备Fe76B12Si12及Fe76B12Si10C2合金的块状纳米软磁材料。研究结果表明,净化玻璃的化学成分、循环过热温度及净化过程中熔融玻璃和合金液的良好排气条件是影响净化效果的主要因素。  相似文献   

2.
Mn—Fe熔体的脱Si过程及Mn—Fe熔体氧位研究   总被引:2,自引:0,他引:2  
通过实验(1350℃ )测定 Mn-MnO2平衡体系 Mn液氧位,验证了 ZrO2(MgO)固体电解质定氧探头可用于测定 Mn-Fe熔体和锰液氧位.电动势-氧位换算关系式为 ln po2-31.56-(69548.8+46427.7×E)/T.使用 BaCO370%-MnO25%-(Fe2O3+BaF2)25%(质量分数)的熔剂对高炉 Mn-Fe脱 Si时,与最高脱 Si率(75%)对应的 Fe2O3含量是12%; Mn-Fe熔体中氧位和 C的活度关系式为 po2× 1012=35.812-0.106×ac; Mn-Fe熔体中氧位和 Mn损( [Mn])关系为po2×1012=6.238+0.679× [Mn].使用 BaCO360%-BaF210%-MnO215%-Fe2O315%熔剂对高炉 Mn-Fe脱Si时, 最高脱 Si率(88.9%)和最高氧位(8.31×10-12 Pa)对应的脱 Si时间为 15 min.脱 Si实验结果表明:脱 Si过程中Mn-Fe熔体的氧位是由熔体中碳氧反应控制的;脱 Si保 Mn的最高氧位是 6.238×10-12 Pa.  相似文献   

3.
液态Ni-Fe合金的超过冷与热力学性质   总被引:3,自引:0,他引:3  
采用熔融玻璃净化法使液态Ni-10%Fe和Ni-35%Fe合金过冷度分别达到371(0.90△T_h)和343K(0.91△T_h).实验测得其超过冷临界过冷度△Th分别为413和376K.根据超过冷的定义导出一种测定深过冷熔体平均比热容的方法,从而得到两种深过冷合金的比热容为41.0和40.7J/(mol·K).据此对快速凝固过程中的焓变△H_(LS),熵变△S_(LS),相变驱动力△G_(LS)以及晶体形核率Ⅰ进行了理论计算.发现尽管过冷度超过了0.2T_L,液态合金仍然发生异质形核.  相似文献   

4.
快速退火热处理Fe-Si-B系非晶薄带的磁性研究了Fe-Si-B系非晶薄带在低于品化温度下低温处理和快速退火处理(FA)对其磁性的影响。单辊法制成20μm厚、7mm宽非晶Fe(76)Cu1Si(13)B(10)及Fe(74)Cu1Nb3Si(12)B...  相似文献   

5.
利用化学镀方法首次成功地制备了Fe-TM-B(TM=Sn,W,Mo-W)合金,采用VSM研究了合金施镀态和热处理后的磁性。结果表明:随镀层中Fe含量的增加和热处理温度的降低,镀层饱和磁化强度出现增加趋势,在B含量分别为14.9at%和9.3at%时,Fe-Sn-B和Fe-W-B镀层的矫顽力出现极小值;Fe-Mo-W-B镀层矫顽力随退火温度的提高而连续增加。Fe-Sn-B和Fe-W-B镀层的剩磁比不  相似文献   

6.
Fe-P-B-Si基非晶合金日本东北大学材料研究所研究了Fe-P-B-Si基非晶合金的软磁性能和宽广的过冷液相区。过冷液相区ΔTx的定义是玻璃转变温度Tg和晶化温度Tx之间的温差,即ΔTx=Tx-Tg。用感应炉熔炼Fe80(P,B,Si)20、Fe8...  相似文献   

7.
利用XRD、DSC以及TEM方法研究了快速凝固Al-20Si-5Fe合金退火态的微观组织、弥散相结构和相转变。结果表明,快凝Al-20Si-5Fe合金组织中存在两种弥散相,δ-Al4FeSi2和初生Si相,退火温度低于310℃时,δ-Al4FeSi2相未明显粗化;当退火温度高于310℃时,亚稳相δ-Al4FeSi2转变成稳定相β-Al5FeSi,β-Al5FeSi相随退火温度的提高而明显粗化。高温  相似文献   

8.
Fe76.5-xCu1NbxSi13.5B9的磁致伸缩样品为Fe73.5Cu1Nb3Si16.5B6和Fe76.5-xCu1NbxSi13.5B9(x=2,3和5)。Fe73.5Cu1Nb3Si16.5B6非晶带经530℃退火,其他成分样品的退火温度...  相似文献   

9.
最近发现Fe Si B Nb Cu系铸造非晶态合金棒(直径约为 0 5mm) ,通过退火晶化可形成由纳米级bcc-Fe晶粒与其周围残留非晶相所组成的显微组织 ,具有良好的软磁性能。新近研究了利用铜模铸造法生产的Fe Si B Nb Cu系非晶态合金棒的部分晶化组织与其磁性能之间的关系。研究时采用了纯金属铁、铌、铜和纯硅和晶体硼作原料配成的混合料 ,在氩气氛中电弧熔炼制得Fe95-x -ySixByNb4Cu1 (原子百分比 )多元金合锭。该合金锭重熔后用铜模铸造法制成不同直径 (≤ 2mm)的合金棒。同时也利用熔体旋淬法制备合金…  相似文献   

10.
纳米晶软磁合金Fe73/5Cu1Nb3Si13.5B9淬态脆化机制研究   总被引:1,自引:0,他引:1  
本文采用正电子湮没、居里点与内耗等方法对纳米晶磁合金Fe73.5Cu1Nb3Si13.5B9淬态脆化机制进行系统研究。研究结果表明FeCuNbSiB淬态脆化是由于发生/构弛豫造成,且其结构弛豫峰温度比常用Fe-B-Si非晶低得我,说明Fe-B-Si非晶低得多,说明FeCuNbSiB比常用Fe-B-Si非晶易产生由结构弛豫造成的淬态脆化。  相似文献   

11.
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   

12.
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   

13.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

14.
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   

15.
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   

16.
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.  相似文献   

17.
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.  相似文献   

18.
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   

19.
An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.  相似文献   

20.
A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.  相似文献   

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