应用石油焦压密技术研究开发优质预焙阳极

将煅前石油焦压密和煅烧，通过体积密度、真密度、显气孔率、粉来电阻率、颗粒抗压碎强度的测试，研究压密煅烧石油焦特性。采用压密煅烧石油焦制成预焙阳极。通过体积密度、真密度、显气孔率、电阻率、耐压强度、透气度的测试。结果表明，压密石油焦能显著地改善预焙阳极的理化性能，使预焙阳极制造过程中沥青加入量控制在13％，预焙阳极的体积密度达到I．65g／cm^3．强度达到50MPa。     

改变石油焦和煤沥青性质对预焙阳极块使用性能的影响

通过对石油焦体积密度、真密度改性研究 ,采用压密石油焦新技术 ,使预焙阳极块生产过程中煤沥青加入量控制在 12 %。通过对煤沥青成分改性研究 ,生产出甲苯不溶物 >2 8%、喹啉不溶物 <2 % ,β树脂含量 >2 5 % ,软化点90℃左右的煤沥青 ,使预焙阳极可以在 <160℃条件下混捏 ,同时提高了煤沥青分散性、润滑性、结合强度、石墨化程度。用上述研究成果 ,实现新型预焙阳极块体积密度 1.6g/cm3、耐压强度 3 5MPa、电阻率 5 0 μΩ·m。与常规方法生产的预焙阳极进行比较 ,研究其改性后的石油焦、煤沥青使用特性 ,满足铝电解工业炭素材料发展要求     

浸渍压密石油焦基预焙阳极块结构与性能研究

本文主要研究了浸渍压密石油焦对预焙阳极块结构与性能的影响.结果表明:以浸渍压密石油焦为骨料制备预焙阳极块时.可以提高试样的体积密度、耐压强度,降低试样的电阻率和显气孔率.浸渍压密石油焦基预焙阳极块试样的理化性能显著优于普通石油焦基、压密石油焦基预焙阳极块试样的理化性能.     

一种新型优质预焙阳极的开发研制

以节能、降耗、减排、低炭宗旨,选择高挥发分煅前石油焦为原料,开发体积密度1.62g/cm3煅后石油焦,控制粒径＞15mm加入量50%,粒径＜1mm加入量20%,煤沥青加入量7.8%,实现预焙阳极体积密度1.64g/cm3;耐压强度51MPa;电阻率48μΩ·m.     

应用改性煤沥青技术研究开发优质预焙阳极(下)

针对我国预焙阳极与国际水平的差距以及我国煤沥青生产使用现状,开发出适合预焙阳极用改性煤沥青,并对其进行基本性能和高温性能的检测。采用热沉降试验方法制备出预焙阳极试样,通过对试样理化性能检测与分析。结果发现,煤沥青组分对预焙阳极的使用性能影响很大。特别是B组分,决定了煤沥青粘结强度,适量调整煤沥青组分有利于提高预焙阳极的使用性能。     

应用改性煤沥青技术研究开发优质预焙阳极(上)

针对我国预焙阳极与国际水平的差距以及我国煤沥青生产使用现状,开发出适合预焙阳极用改性煤沥青,并对其进行基本性能和高温性能的检测。采用热沉降试验方法制备出预焙阳极试样,通过对试样理化性能检测与分析。结果发现。煤沥青组分对预焙阳极的使用性能影响很大。特别是β组分,决定了煤沥青粘结强度,适量调整煤沥青组分有利于提高预焙阳极的使用性能。     

煤沥青改性对铝电解预焙阳极块使用性能的影响

通过对煤沥青研究，进一步了解煤沥青中α树腊、β树脂的性质，以不同含量，分别与石油焦进行混捏，制成煤沥青加入量相同，沥青中α树脂、β树脂含量不同的预焙阳极。通过理化指标检测，确定二种树脂成分对预焙阳极影响，探索其规律性，为预焙阳极煤沥青的选择提供依据。最终达到提高预焙阳极质量的目的。     

优化工艺强化管理降低炭阳极生产中的原料消耗

铝用炭阳极生产的主要原料为石油焦和改质沥青,本文主要阐述了两种原料单耗的计算办法,并结合企业的实际生产状况,从优化工艺和强化管理的角度,提出了预焙阳极生产过程中,控制石油焦、沥青原料单耗的主要途径和措施.     

铝用预焙阳极生产对石油焦变化趋势采取的策略

随着中国使用进口石油的增加,石油焦的质量不断恶化,适合生产预焙阳极的石油焦量不断萎缩,给预焙阳极生产带来较大的影响。为了应对这一趋势,本文提出一些应对措施和策略,希望对我国预焙阳极技术持续发展支撑铝工业不断进步起到一些促进作用。     

原料性能和配方对炭阳极生坯成型后膨胀行为的影响

选取工业用三种煅后焦和两种沥青制备铝用预焙阳极生坯,采用实验室方法考察煅后焦和沥青性能、煅后焦粒度组成、沥青配比及混捏温度对阳极生坯成型后膨胀行为的影响。结果表明,沥青在糊料中比例越高,混捏温度越高,阳极生坯成型后体积膨胀越小;相对于中温沥青,改质沥青限制阳极生坯膨胀效果更好,且当改质沥青含量足够大时,阳极生坯会出现体积收缩;阳极生坯成型后膨胀与生坯密度并非直接关联,而与煅后焦闭气孔率成反比,与煅后焦真密度成正比。所获基础技术数据可供实际生产应用参考。     

Nb-Hf合金表面Si-Ti-Cr硅化物涂层在恒温氧化和热震中的高温抗氧化性能（英文）

为了提高Nb-Hf合金的高温抗氧化性能,采用浆料烧结和高温渗透制备了Si-Ti-Cr硅化物涂层。分析了Si-Ti-Cr硅化物包覆的Nb-Hf合金样品在恒温氧化和高温热震条件下的抗氧化性能,揭示了Si-Ti-Cr涂层高温恒温氧化和高温热震条件下的失效机理。结果表明,在1800℃恒温氧化5 h条件下,涂层的增重为7 mg/cm²;在1700℃热震循环50周次和恒温氧化5 h条件下,涂层的最大增重为1.8mg/cm²。硅化物涂层在1800℃恒温氧化环境下和1700℃热震/恒温氧化环境下具有优异的抗氧化性能。     

TiAl基合金离子渗碳与高温抗氧化性研究

研究了辉光离子渗碳处理对TiAl基合金的渗层组织、表面硬度和抗高温氧化性的影响。实验显示,渗碳处理可在TiAl基合金的表面形成由碳化物和过渡层组成的复合相结构,经不同渗碳处理的试样,其表面硬度和抗高温氧化性均得到明显提高。     

TiA1基合金离子渗碳与高温抗氧化性研究

研究了辉光离子渗碳处理对TiA1基合金的渗层组织、表面硬度和抗高温氧化性的影响。实验显示。渗碳处理可在TiA1基合金的表面形成由碳化物和过渡层组成的复合相结构，经不同渗碳处理的试样，其表面硬度和抗高温氧化性均得到明显提高。     

Al 2O 3 PARTICLE REINFORCED COPPER MATRIX COMPOSITE USING FOR CONTINUOUS CASTING MOULD

１．ＩｎｔｒｏｄｕｃｔｉｏｎＭｏｕｌｄｉｓａｋｅｙｐａｒｔｏｆｃｏｎｔｉｎｕｏｕｓｃａｓｔｉｎｇ．Ｔｈｅｍｏｕｌｄｓｕｒｆａｃｅｃｏｎｔａｃｔｓｗｉｔｈｍｏｌｔｅｎｓｔｅｅｌ（１５００℃１６００℃）ａｎｄｓｏｌｉｄｐｒｏｔｅｃｔｉｖｅｓｌａｇｗｈｉｌｅｔｈｅｂａｃｋｆａｃｅｏｆｔｈｅｍｏｕｌｄｉｓｃｏｏｌｅｄｂｙｗａｔｅｒ．Ｉｎｏｒｄｅｒｔｏａｓｓｕｒｅｔｈｅｓｔｅｅｌｂｌａｎｋｐｕｌｌｅｄｏｕｔｃｏｎｔｉｎｕｏｕｓｌｙ,ｔｈｅｍｏｕｌｄｍｕｓｔｓｔｒｉｃｔｌｙｋｅｅｐｔｈｅｄｅｓｉｇｎｄｉ…     

预焙阳极生阳极体积密度偏低原因分析及改进

预焙阳极生阳极体积密度的高低对焙烧后阳极制品的质量有直接影响,本文就生产过程中出现的生阳极体积密度偏低情况进行深入分析,分别从原料、配料、混捏、成型等工序查找原因,并针对具体问题做出有效改进,从实施效果看,提高了生阳极体积密度,改善了阳极的某些性能。     

La-TZM合金板材制备及其氧化行为

采用粉末冶金法,在TZM合金的基础上,固-液掺杂稀土元素La,且以有机碳源硬脂酸替代传统的石墨粉引入C元素,经混料、压制成形、高温烧结、热轧、温轧、冷轧等工艺制备La-TZM合金板材。将La-TZM合金板材分别在300、450、600、800、1000℃进行高温氧化实验,通过质量损失率、差热分析等实验方法研究其氧化行为。研究表明:La-TZM合金板材的抗拉强度为1361.74 MPa,伸长率为8.81%,较传统的TZM合金均有显著提高。La-TZM合金板材纤维组织细长,组织致密;第二相细小且分布均匀。其细小的氧化镧及第二相颗粒钉扎在晶界,生成的氧化物会在基体表面形成致密氧化物覆盖层,可以有效地阻碍氧向基体的侵入,表面不易氧化,从而使TZM合金的抗氧化性能提高,扩展了TZM合金的使用温度范围。     

微弧氧化对TC4钛合金高温抗氧化性能的影响

采用直流稳压电源,在Na2SiO3、Na3PO4电解液中对TC4钛合金表面进行微弧氧化处理,研究了微弧氧化对TC4钛合金高温抗氧化性能的影响.结果表明,经微弧氧化的TC4合金高温抗氧化性能明显优于TC4钛合金;在750℃循环氧化100h后,经300V电压微弧氧化60 min的TC4钛合金的氧化增重为7.8 mg/cm2,而未经微弧氧化处理的TC4钛合金氧化增重为30.51 mg/cm2;随着微弧氧化时间增长和电压的增大,微弧氧化TC4钛合金的高温抗氧化性能也增强.     

Oxidation resistance of SHS Fe–Al–Si alloys at 800 °C in air

Alloys formed by Fe–Al intermediary phases have lower density than common metallic high-temperature alloys and good high-temperature oxidation resistance. Previously it was proved that silicon additions to these alloys enable to produce them efficiently by reactive sintering and improves the wear resistance. In this work, the oxidation resistance of the novel Fe–Al–Si alloys containing 10–30 wt. % of aluminium and 5–30 wt. % of silicon produced by the reactive sintering technology was tested. Cyclic and isothermal oxidation tests were carried out at 800 °C in air. Tested alloys exhibit excellent oxidation resistance, which increases with silicon content up to 20 wt. %. The reasons are discussed in terms of the phase composition of the oxide layer and the changes in chemical composition under the oxide layer during oxidation.     

High-temperature oxidation behaviors of Fe-Cr-Al bulk and powder-sintered materials

In this study, cast bulk specimens and powder sintered specimens were produced from a Fe-22% Cr-5.8% Al alloy, which has been drawing industrial attention for its outstanding high-thermal and oxidation resistance as well as for its applicability as a filter and support material. The high-temperature oxidation behaviors of the specimens were compared and analyzed. Two types of specimens were subjected to 24-hour isothermal oxidation (temperatures of 900 °C, 1000 °C, and 1100 °C and a gas atmosphere of 79% N₂+21% O₂) to understand their high-temperature oxidation properties. The oxidized specimens were examined via X-ray, SEM, FE-SEM, and EPMA for microstructure and oxide analyses. The results of the oxidation tests showed that both bulk and powder-sintered specimens gained weight as temperature increased, with the powder sintered specimens gaining far more weight than the bulk specimens. As the temperature increased, the bulk specimens showed sequential formation of Al ₂ O₃, Cr₂O₃, and Fe₃O₄ oxide layers. The stable Al₂O₃ on the surface of the bulk specimens was found to play a role in arresting the rapid growth of oxide layers. In the powder-sintered specimens, however, the internal diffusion of O₂ easily took place along the powder interfaces. As a result, far more oxidation occurred in the powder-sintered specimens than in the bulk specimens. Cracks and disintegration of the oxide layers were also found to have occurred as the temperature increased. The high-temperature oxidation mechanisms of bulk and powder-sintered materials in relation to temperature increase are further discussed.     

Evaluation of microstructure and phase relations in a powder processed Ti-44AI-12Nb alloy

Titanium aluminides based on the ordered face-centered tetragonal γTiAI phase possess attractive properties, such as low density, high melting point, good elevated temperature strength, modulus retention, and oxidation resistance, making these alloys potential high-temperature structural materials. These alloys can be processed by both ingot metallurgy and powder metallurgy routes. In the present study, three variations of the powder metallurgy route were studied to process a Ti-44Al-12Nb (at. %) alloy: (a) cold pressing followed by reaction sintering (CPprocess); (b) cold pressing, vacuum hot pressing, and then sintering (HP process); and (c) arc melting, hydride-dehydride process to make the alloy powder, cold isostatic pressing, and then sintering (AM process). Microstructural and phase relations were studied by x-ray diffraction (XRD) analysis, optical microscopy, scanning electron microscopy with an energy-dispersive spectrometer (SEM-EDS), and electron probe microanalysis (EPMA). The phases identified were Ti₃AI and TiAl; an additional Nb₂AI phase was observed in the HPsample. The microstructures of CPand HP processed samples are porous and chemically inhomogeneous whereas the AM processed sample revealed fine equiaxed microstructure. This refinement of the microstructure is attributed to the fine, homogeneous powder produced by the hydride-dehydride process and the high compaction pressures.