SiCw／Al—Li—Cu—Mg—Zr复合材料压铸工艺的研究

本文利用挤压铸造法成功制备了ＳｉＣｗ／Ａｌ－Ｌｉ－Ｃｕ－Ｍｇ－Ｚｒ复合材料。采用化学分析，电子探针和扫描电镜等分析测试手段对材料进行化学分析和组织观察。结果表明，所获得得的复合材料样品中晶须分布均匀，各合金元素含量均可控制在成分设计范围内。拉伸试验结果表明，ＳｉＣｗ／Ａｌ－Ｃｕ－Ｍｇ－Ｚｒ复合材料具有较优异的综合拉伸性能。     

SiC_w／Al－Li－Cu－Mg－Zr复合材料压铸工艺的研究

本文利用挤压铸造法成功制备了ＳｉＣ_ｗ／Ａｌ－Ｌｉ－Ｃｕ－Ｍｇ－Ｚｒ复合材料。采用化学分析、电子探针和扫描电镜等分析测试手段对材料进行化学分析和组织观察。结果表明，所获得的复合材料样品中晶须分布均匀，各合金元素含量均可控制在成分设计范围内。拉伸试验结果表明，ＳｉＣ_ｗ／Ａｌ－Ｌｉ－Ｃｕ－Ｍｇ－Ｚｒ复合材料具有较优异的综合拉伸性能。     

ZL201合金液相线铸造与二次加热的合金组织

为了研究半固态金属的成型规律,采用电子显微镜及图像分析仪,研究了近液相线半连续铸造ZL201合金的微观组织及其在二次加热过程中的变化.研究表明,在液相线温度下半连续铸造的ZL201合金组织为均匀、细小的蔷薇状组织,晶粒的平均等积圆直径为43.6μm,晶粒平均圆度为1.88.经二次加热后,铸造组织逐渐转变为等轴晶.在620℃下加热20min后,晶粒平均等积圆直径为111μm,晶粒平均圆度1.42.在640℃下加热20min后,晶粒平均等积圆直径为108μm,晶粒平均圆度1.58.研究表明,近液相线半连续铸造可以获得理想的ZL201合金半固态坯料.     

惯性导航仪用新型铸造铝合金研究

研究了惯性导航仪用新型Ａｌ－Ｚｎ－Ｍｇ系高尺寸稳定性铸造铝合金。新型合金为ＺＡｌＺｎ４Ｍｇ４，具有较高强度及良好的综合性能。研究了Ｚｎ、Ｍｇ、Ｃｕ、Ｔｉ及Ｚｒ等元素和热处理工艺对合金性能的影响，并测定了合金的物理性能和尺寸稳定性。     

(YCa)F3助烧AlN陶瓷的显微结构和热导率

采用（ＣａＹ）Ｆ_３为助烧结剂，低温烧结（１６５０℃， ６ｈ）制备出热导率为２０８Ｗ／ｍ·Ｋ的ＡＩＮ陶瓷，在烧结过程中，热导率随保温时间的变化服从方程：λ（ｔ）＝λ∞－△λ（０）·ｅ~（－ｔ／ｒ）·用ＳＥＭ、 ＳＴｈＭ、 ＴＥＭ和 ＨＲＥＭ对 ＡＩＮ陶瓷的显微结构及其对热导率的影响进行了研究，结果表明，晶粒尺寸对ＡＩＮ陶瓷热导率的影响可以忽略，而分隔在ＡＩＮ晶粒之间的晶界相会降低热导率。     

船用铝镁合金剥落腐蚀机理的研究

应用ＡＳＴＭＧ６６－８６化学浸泡试验、ＡＳＴＭＧ６７－８６硝酸失重试验，金相、ＳＥＭ、ＴＥＭ观察及电化学方法对不同冷变形量和经稳定化处理的９种Ａｌ－Ｍｇ合金试样的剥落腐蚀行为进行了研究。结果表明：由于冷变形被拉长，晶粒的晶界上连续分布析出相β（Ｍｇ２Ａｌ３）在腐蚀介质中会成为阳极活性通道；闭塞区内腐蚀条件的恶化，将加速与轧制表面平行的阳极活性通道的腐蚀；腐蚀产物的楔入作用造成材料分层剥落；Ａｌ－Ｍ     

真空铸造高强度C／Mg复合材料

本文介绍用真空铸造法制造抗拉强度超过１０００ＭＰａ的高强度Ｃ／Ｍｇ复合材料。将Ｔ３００纤维经Ｃ－Ｓｉ－Ｏ梯度涂层处理后单向排布于型腔内，在真空下注入ＺＭ—５合金液，凝固后即得Ｃ／Ｍｇ复合材料零件或试样。试样的抗拉强度在纤维体积分数为０．３５时达１０５０ＭＰａ。本文讨论Ｃ－Ｓｉ－Ｏ梯度涂层对获得高强度复合材料的作用。     

ZG20Mn2钢摇臂断裂分析

通过宏，微观检验，成分分析及力学性能测试，得出ＺＧ２０Ｍｎ２钢摇臂断裂是由于晶粒粗化和铸造缺陷的存在使强度和塑性急剧下降所致。     

(YCa)F3助烧AIN陶瓷的显微结构和热导率

采用（ＣａＹ）Ｆ３为助烧结剂,低温烧结（１６５０℃,６ｈ）制备出热导率为２０８Ｗ／ｍＫ的ＡＩＮ陶瓷,在烧结过程中,热导率随保温时间的变化服从方程,λ（ｔ）＝λ∞－△λ（．３＾－６／ｒ,用ＳＥＭ、ＳＴｈＭ、ＴＥＭ和ＨＲＥＭ对ＡＩＮ陶瓷的显微结构及其对热导率的影响进行了研究。结果表明,晶粒尺２对ＡＩＮ陶瓷热导率的影响可以忽略,而分隔在ＡＮＩ晶粒之间的昌界相会降低热导率。     

一种新型铝基功能复合材料的研究

采用铸造凝固复合法将铝和在４￣１４μｍ波长范围内具有强辐射能力的ＴＭ颗粒复合在一定，制成Ａｌ／ＴＭ红外辐射功能复合材料，Ａｌ／ＴＭ复合材料组织致密，颗粒分布均匀。研究发现，Ａｌ／ＴＭ复合材料在红外光谱４￣１４μｍ的光谱辐射率和光谱辐射度比铝有很大提高。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

Analysis of anisotropy of properties on the basis of studies of texture of coarse-grained ingots of thermoelectric materials

An analysis of anisotropy of the properties of a Bi₂Se_0.3Te_2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.