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利用旋转圆盘装置研究TiFiNiNb合金和0Crl3Ni5Mo不锈钢的空蚀行为,并用洛氏硬度仪模拟空蚀过程中微射流所产生的局部载荷对TiNiNb合金和0Cr13Ni5Mo不锈钢的作用,结果表明,TiNiNb合金的抗空蚀性能优于0Crl3Ni5Mo。在压痕试验中,TiNiNb合金能吸收高于0CI13Ni5Mo的弹性能,该性能特点使TiNiNb合金在空蚀过程中能吸收和释放较多的冲击能量,减少损失,呈现良好的抗空蚀性能。 相似文献
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分析了双击式螺旋压力机的能量特性,提出了双击能量比图,简要介绍了1600kN双击式螺旋压力机能量测试结果。 相似文献
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铝合金微弧氧化过程中能量转换的实验研究 总被引:13,自引:0,他引:13
采用量热实验方法初步测定了L2Y和LY12铝合金微弧氧化过程中电能转化为热能的大小,结果表明,总电能ΔW转化为热能ΔQ的比值ΔQ/ΔW在50% ̄80%之间变化,其值随溶液浓度升高而增加,相同实验条件下,纯铝的ΔQ/ΔW值比Al-Cu-Mg系合金LY12的低。在20 ̄85℃范围内,溶液吸热量与总电能比值随溶液温度升高略有降低。微弧氧化过程中电能除部分转化为H2、O2析出能、光能和声能等方面外,大部分 相似文献
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本文通过对300kA大型预焙槽阴极结构的综合论述,指出该阴极结构的特点和生产中应采取的一些相应措施,以期对实际生产有一定指导意义。 相似文献
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铝电解槽节能工作已成为现代铝行业所面临的重要工作。本文在兰州铝厂“三场”测试基础上,依据区域能量自耗理论,并结合国内外科研工作实际,对铝电解槽节能现状及其潜力,进行了综合评述与介绍。 相似文献
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在日益发展的亚微晶粒、有时甚至是纳米晶粒的先进材料的设计方面,结构特性的相互关系起着重要的作用:在这方面,分析电子显微镜法(AEM)提供了尤其适合硬质材料的综合鉴定方法:用来获得结晶信息的电子衍射法和高分辨率电镜法,以及尤其像能量过滤透射电镜法(EFTEM)和电子能量损失光谱法(EELS)等几乎能够进行原子分辨率分析的新方法:本文利用EFTEM和HREM方法着重研究了WC初始粉末和添加VC和Cr3C2的WC-Co烧结复合材料,以便在超细WC粉末的烧结过程中控制晶粒的长大。本文旨在查明粉末和烧结材料中添加元素的分布。 相似文献
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分析了单极槽的电压效率(由槽间联接母线间的槽电压损失引起的)和双极槽的电流效率(由旁路电流引起的)发现:两者的计算结果相近,其中单极槽的电压效率是在选择最佳的母线横截面下计算的,还对NaCl-LiCl-AlC13熔融电解质生产铝的双极槽由于旁路电流造成的电流效率损失进行了计算。 相似文献
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1. Introduction The difference interference contrast (DIC) method is one of the most exciting inspection and powerful analysis methods in modern materials metallographic exami- nations [1], which has many advantages. Specimens preparation is relatively simple. For certain specimens, their microstructure could be observed without etching under the microscope by using the DIC method as the polished specimen surface is preserved. The obser- vation of the specimen surface via the microscope has… 相似文献
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Margarida Taborda Duarte H. Y. Liu S. Q. Kou P. -A. Lindqvist K. Miskovsky 《Journal of Materials Engineering and Performance》2005,14(1):104-111
The importance of the microstructural parameters in rock mechanical behavior has been investigated by several authors. Moreover,
the Weibull statistical model has been used to characterize the heterogeneity of several materials on the basis of the concept
that the microscopic defects within the material determine their mechanical strength. The modeling of different rocks is a
topic that is fundamental for the prediction of rock fragmentation. In this article, the analysis of rock microstructure is
performed using the microstructural modeling approach, which consists of the simplification, quantification, and modeling
of the main properties of rock microstructure. The grain size, grain shape, and microcracks are modeled by means of statistical
density functions, namely, Cauchy, chi-squared, exponential, extreme value, gamma, Laplace, normal, uniform, and Weibull.
It is found that the Weibull distribution is the most appropriate statistical model of the grain size and grain shape, when
compared with the other eight statistical models. Regarding microcracks, the results show that the gamma distribution is the
most appropriate model. The Weibull and gamma distributions are then used to analyze the heterogeneity of the microstructure.
This is done by comparison of the statistical models of each microstructural property evaluated in several thin sections of
the same rock. It is found that with respect to grain size and grain shape, the rock is homogeneous, while the size distribution
of the microcracks shows a clear trend toward less homogeneity. The microstructural modeling approach is important for modeling,
characterizing, and analyzing the microstructure of rock material. Among other applications, it can be used to explain differences
in the mechanical behavior obtained in testing several specimens. 相似文献
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Zhiyong Xu Jiann-Yang Hwang Bowen Li Xiaodi Huang Howard Wang 《JOM Journal of the Minerals, Metals and Materials Society》2008,60(4):29-32
Zinc oxide (ZnO) is a unique material that has prompted a vast amount of research. Various morphologies and sizes of ZnO materials
have led to a wide range of promising applications. Although research related to the applications of ZnO is progressing rapidly,
it has been an enormous challenge to produce uniform ZnO materials. A unique synthesis method to produce ZnO materials with
various morphologies has been studied and is presented in this paper. Field-emission scanningelectron microscopy has been
utilized to characterize ZnO materials in this study to show how the synthesis conditions control the morphologies of ZnO. 相似文献
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针对某复杂曲面薄壁不锈钢工件精密脉冲TIG焊中的焊缝跟踪问题 ,本文研究了一种基于视觉传感的高精度、高实时性焊缝跟踪技术。根据脉冲TIG焊的工艺特点 ,该技术通过选择特定波长的滤光片及合理的曝光时刻 ,采用工业CCD摄像机获取可直接分辨出焊缝、熔池和钨极的清晰、放大的焊接区图像。采用VC语言设计的图像处理算法 ,可以快速准确地识别出焊缝中心线 ,提取钨极偏离焊缝中心线的方向和距离 ,驱动步进电机调节焊炬位置 ,实现高精度、高实时性的焊缝跟踪。试验结果表明 ,该技术的单幅图像处理周期小于 12 0ms,能实现焊炬运动方向与焊缝偏差角小于 3 0°的焊缝跟踪 ,满足了复杂曲面的薄壁不锈钢工件的精密焊接要求。 相似文献
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冷加工对含Mn铝合金管腐蚀行为的影响 总被引:2,自引:0,他引:2
采用SEM,TEM,动电位极化和浸泡实验研究了机械冷加工变形对汽车散热器高Mn(0.22%,质量分数,下同)和低Mn(0.08%)铝合金管在0.6 mol/L NaCl(pH=6)和SWAAT(ASTM G85,pH=3)溶液中的腐蚀行为的影响.电化学极化测试表明,无形变时高Mn铝合金直管的点蚀电位最高;但冷加工能降低高Mn铝合金弯曲表面的点蚀电位,而对低Mn铝合金的点蚀电位没有明显影响.TEM观察发现,冷加工后高Mn铝合金中有大量纳米尺度的富Mn析出相,在低Mn铝合金中却没有观察到这种析出相,阴极极化测试表明,富Mn相能显著促进阴极反应,富Mn相相对Al基体为阴极相,因而是点蚀萌生的部位.添加Mn尽管有利于提高铝合金的耐蚀性,但机械冷加工会弱化这一效应. 相似文献