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二氧化硅在真空低价法制备铝过程中的歧化行为研究 总被引:4,自引:0,他引:4
本文引入"物质吉布斯自由能函数法"讨论在低价氟化法制备铝过程中,二氧化硅在不同压力和温度下生成低价氧化硅及其分解的热力学条件并进行了实验验证.研究得出:在100kPa时,二氧化硅与还原剂碳反应在1937K以上才能生成低价氧化硅;而当系统残余压力在100Pa~10Pa内时,在1463K~1352K以上即可以生成低价氧化硅;体系压力在100Pa~10Pa范围内,即低价氧化硅歧化分解温度在1535K~1415K间进行.实验结论:采用真空碳热还原铝土矿实验,在系统压力为150Pa,反应温度为1450℃时,得到含硅为4.87%的金属铝,铝纯度达到95.13%.实验验证了理论研究的正确性,为生产工艺的研究提供了热力学理论依据和实验基础. 相似文献
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真空下低价氯化铝生成及其分解热力学简化研究 总被引:2,自引:1,他引:1
利用新的热力学研究方法一"物质吉布斯自由焓函数法"对不同压力下三氧化二铝生成低价一氯化铝及低价一氯化铝分解进行热力学条件的简化计算.研究得出:在100 kPa时,三氧化二铝在有还原剂碳存在下与三氯化铝反应需在2069.75 K以上才能生成低价一氯化铝,而当系统压力在100~10 Pa内时,温度在1294.49~1374.79 K以上就可以生成低价一氯化铝;在压力为105~10 Pa范围,1538.061~1049.311 K以下都可以进行一氯化铝的岐化分解,简化计算与实验事实更接近. 相似文献
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真空下低价二氯化铝生成及其分解热力学简化研究 总被引:1,自引:0,他引:1
对不同压力下三氧化二铝与碳、氯化铝在低价氯化物法炼铝过程中生成低价二氯化铝及低价二氯化铝分解的热力学条件进行简化计算.研究得出:在100 kPa时,三氧化二铝与还原剂碳反应在1896 K以上才能生成低价二氯化铝;而当系统压力在100~10 Pa内时,温度在1294~1396 K以上就可以生成低价二氯化铝;在压力为105~10 Pa范围,1195~829 K以下都可以进行二氯化铝的岐化分解,而且温度降低,温度越低,歧化分解越容易进行,且简化计算与实验事实更接近. 相似文献
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低价氟化物法从氧化铝提取铝的研究 总被引:1,自引:1,他引:0
利用低价氟化铝歧化反应,用碳作还原剂,在真空条件下,从氧化铝中提取铝进行了实验研究.实验结果表明不同粘接指数的煤混合物作为还原剂可以防止喷料;同时得到较优的实验参数冰晶石与氧化铝的质量比为51,氧化铝的还原率达到80%以上;固定碳过量3.02倍时,还原率将近80%;温度在1400℃时金属铝纯度达92.54%.为下一步从低品位含氧化铝原料中直接提取金属铝提供依据. 相似文献
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王卫军 《理化检验(物理分册)》2012,(4):241-244
以3104铝合金铸造扁锭为例,介绍了变形铝及铝合金铸锭显微疏松检验试样的制备过程及其注意事项,并给出了在依据标准图谱判定显微疏松等级过程中容易出现的问题。通过对3104铝合金铸锭在各个方向进行检验,得出了显微疏松在变形铝及铝合金铸锭中的分布规律。 相似文献
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Aluminium metaphosphate glass-ceramics 总被引:1,自引:0,他引:1
Abtract AIP3O9 glass-ceramics were prepared by crystallization of glasses at 750–1100°C. Crystallization of AIP3O9 and AIPO4 at lower temperatures is favoured by addition of 5–10 mol % Li2O, Na2O or AIF3, whereas crystallization is hindered by 5–10 mol % B2O3, BPO4, SiO2, TiO2, Nb2O5 or Ta2O5. Additives such as TiO2, ZrO2, MgF2, CaF2 and Pt, frequently useful in nucleating silicate glasses, are ineffective in AIP3O9 glasses. AIPO4, resulting from the P2O5 loss during melting, forms at the surface of melted glass samples. AIP3O9 forms in the bulk as elongated columnar or lamellar crystals with grain sizes of 0.5–2.0 m. Li2O-doped AIP3O9 is inhomogeneous with coarse intergranular regions and glassy regions. Dielectric constants vary from 5.0–5.2. 相似文献
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Guoxin SUI Zhongguang ZHENG Chengti ZHOU Changxu SHI Institute of Metal Research Academia Sinica Shenyang ChinaBenlian ZHOU International Centre for Materials Physics Academia Sinica Shenyang China 《材料科学技术学报》1993,9(5):382-384
A new kind of superhybrid composite material,vinylon reinforced aluminium laminate (VIRALL),hasbeen developed by laminating the vinylon/epoxy prepreg layers and the aluminium alloy sheetsalternatively.The mechanical properties of VIRALL laminate have been tested and the results are dis-cussed in terms of laws of mixtures.About a 24% increase in tensile strength and a 36%decrease intensile modulus to that of the corresponding aluminium were found,which kept good agreementwith the laws of mixtures.Compared with the corresponding aluminium,VIRALL has lighter densityand lower price.VIRALL is hoped to be a partial substitute for the civil aluminium alloy in the future. 相似文献
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L. Krishnamurthy B. K. Sridhara D. Abdul Budan 《Materials and Manufacturing Processes》2007,22(7):903-908
Aluminium matrix composites find wide applications in the present industrial scenario due to their desirable properties. Study of the effect of process parameters on machinability of aluminium matrix composites is of paramount importance in the field of manufacturing engineering. Machining of a composite depends on the properties and relative content of the reinforcement and the matrix materials as well as on its response to the machining process. In this article, investigations on the machinability aspects of aluminium-silicon carbide and aluminium-graphite composites are presented. Experiments have been carried out through the Design of Experiments technique and regression machinability models have been developed, which express the degree to which the resultant force depends upon the cutting parameters and the percentage of reinforcement present in the aluminium matrix composites machined. A comparative study of the effect of cutting parameters on the resultant force has been presented. 相似文献
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Aluminium foams for transport industry 总被引:12,自引:0,他引:12
Foamed materials are widespread in transportation industry applications. While polymeric foams have been applied for many years foamed metals are now beginning to move into the focus of interest. A powder metallurgical method which allows the production of aluminium foams with porosity levels up to 90% is described. The foams typically have closed pores and densities ranging from 0.4 to 1 g cm−3, so that this foamed metals float on water. The unique mechanical properties of metal foams are described. The density dependence of metal foam properties is shown with the Young's modulus, flexural strength and compression strength as examples. A non-linear dependency of these properties on the density is found and discussed. The discussion then focuses on the energy absorption properties of aluminium foams and tools to select appropriate foams for a given energy absorption task. 相似文献