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71.
B. V. Korzoun L. A. Makovetskaya V. A. Savchuk V. A. Rubtsov G. P. Popelnyuk A. P. Chernyakova 《Journal of Electronic Materials》1995,24(7):903-906
Twenty alloys of various compositions in the Cu2Se-Al2Se3 system were prepared and investigated. The T(x) phase diagram of the Cu2Se-Al2Se3 system was obtained from x-ray diffraction, differential thermal analysis, and microstructure investigation for the first
time. The homogeneity region of the CuAlSe2 semiconducting compound was established.
Previous articles by this author were presented with the spelling of his name as B.V. Korzun. 相似文献
72.
73.
对铸造高性能合金Lewmet55进行了化学成分设计,确定了该合金中镍、铬、钼、铜和硅的含量。采用金相显微镜和X射线衍射相结合的方法,分析了该合金的显微组织,并采用多种腐蚀试验方法研究其耐腐蚀行为。着重研究了不同热处理制度对铸造高性能合金的均匀腐蚀、晶问腐蚀、点蚀和电化学腐蚀性能的影响。试验结果表明,Lewment55合金经1250℃×1.5h水冷固溶处理后,在高温浓硫酸介质中具有良好的耐蚀性,以及较好的抗晶间腐蚀、点蚀和电化学腐蚀性能。 相似文献
74.
The behavior during creep in shear of eutectic indium-tin joints on copper and nickel substrates was examined in order to
determine the effect of creep deformation on the microstructure of the alloy. Primary creep was absent in all the samples
tested. The stress exponent at 20° C was much higher for samples on nickel than for those on copper, indicating a different
creep deformation mechanism. Also, the microstructure within the indium-tin joints differed significantly with a change of
substrate. Samples with a nickel substrate showed a colony microstructure that was not observed in those with a copper substrate.
Thus, eutectic morphology is important in determining deformation mechanism during creep. The microstructure within the joints
in tested and untested regions of the samples was effectively the same. This is quite distinct from the behavior of eutectic
lead-tin observed in previous work. Lead-tin formed a recrystallized band of material along a region of concentrated shear
deformation. While the deformation pattern in the indium-tin samples appeared to be the same as for lead-tin, the microstructural
changes did not occur. This implies that the behavior observed in lead-tin is not universal to eutectic alloys. 相似文献
75.
Heat evolution of high-volume fly ash concrete 总被引:2,自引:0,他引:2
Cengiz Duran Ati? 《Cement and Concrete Research》2002,32(5):751-756
In this paper, the results of a laboratory investigation conducted with heat evolution of high-volume fly ash (HVFA) concrete are presented. Heat evolution of concrete was studied by measuring the temperature increase in concrete under adiabatic curing condition. Characteristic of heat evolution of fly ash concrete was found to be strongly dependent on the replacement level of fly ash and dosage of superplasticizer used to maintain workability. It was also found that using fly ash as cement replacement resulted in a reduction on the maximum temperature rise. Increasing the replacement level of fly ash caused lower temperature rise in concrete. Superplasticizer caused a delay in peak temperature rise time; this is taken as an indicator that high-dosage superplasticizer used in concrete caused retardation in hydration of cement. Concretes having similar ingredients showed similar peak temperature rise whether they are superplasticized or not. 相似文献
76.
O. V. Konstantinova A. V. Kuz’mov V. V. Skorokhod M. B. Shtern 《Powder Metallurgy and Metal Ceramics》2007,46(1-2):25-31
A theoretical method for determining the percolation limit and effective conductivity of composites based on polydisperse
mixtures of insulator and conductor powders is proposed. The effect of the particle size ratio between the insulator and conductor
on the percolation limit and effective conductivity is studied. Numerical simulation of the microstructure, effective properties,
and percolation limit in composites is discussed.
__________
Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 1–2(453), pp. 31–40, 2007. 相似文献
77.
Combined-Stage Sintering Model 总被引:8,自引:0,他引:8
James D. Hansen Richard P. Rusin Mao-Hua Teng D. Lynn Johnson 《Journal of the American Ceramic Society》1992,75(5):1129-1135
By focusing on the similarities between the three stages of sintering, a single equation is derived that quantifies sintering as a continuous process from beginning to end. The microstructure is characterized by two separate parameters representing geometry and scale. The dimensionless geometry parameter, denoted T, comprises five scaling factors that relate specific microstructural featuers (e.g., surface curvature) to the scale (grain diameter). Calculations of T from experimental data show (a) agreement with computer simulations of initial-stage sintering, (b) the effect of surface diffusion on T, and (c) changes in T with microstructural evolution during sintering. Application of the model to the design of firing schedules and the study of microstructural geometry effects on sintering is discussed. 相似文献
78.
论黄河三角洲流路演变及河口治理的指导原则 总被引:5,自引:0,他引:5
通过分析黄河三角洲流路演变中溯源堆积及溯源冲刷对典河下游河道影响的范围,幅度和作用历时,提出在黄河泥沙从根本上减少之前,河口治理的指导原则应是在有利于工农业发展和有利于防洪防凌前提下,有计划地安排河口流路。 相似文献
79.
添加尖晶石对氧化锌压敏电阻性能的影响 总被引:1,自引:0,他引:1
通过添加尖晶石(Zn7Sb2O(12))改性研制出电位梯度为100V/mm左右,压敏电压在82~150V,通流容量可达1600A/cm2,漏电流<2μA系列压敏电阻器,从而满足了国内电话交换机行业对82V、100V、120V、150V压敏电阻器的电性能要求。从工艺的角度解释了尖晶石对氧化锌瓷晶粒的作用原理,并分析了尖晶石的微观结构及粒度对瓷片电性能的影响。 相似文献
80.
40Cr钢试样经不同热处理后在空气中用CO2连续激光束进行辐照,以穆斯堡尔谱学研究试样在辐照后的组织结构变化。试验结果表明,调质预处理后再进行激光辐照的试样,不仅残作产奥氏体含量较低,而且其中碳的含量最低。 相似文献