Ce对过共晶Al—Si合金熔体粘滞性和结构的影响

研究了Ce对Al—16％Si合金熔体粘滞性的影响。结果表明：Ce的加入增加了合金熔体的粘度，且随着Ce含量的增加粘度值也增加。结合加入Ce的Al—16％Si合金氢含量的变化、凝固组织和DSC曲线研究了熔体结构的变化，分析了粘度与液态结构变化之间的关系。     

Influence of process parameters on thermal-rate treatment of ZA42 alloy

Sand casting process and directional solidification technique combining thermal-rate treatment(TRT) were used. The influence of process parameters on TRT was investigated according to the values of impact toughness. At the same time, the mechanism of TRT was discussed. The results showed that TRT can improve the impact toughness of this alloy, while the hardness is basically constant. The time of heat preservation should not be more than 5min. Different forms of cooling intensification additive have different effects among which the zinc ingot solidified in graphite mold is the best one that can improve impact toughness of samples by more than 80%. With increasing the cooling temperature, the value of α(Al) crystal lattice constant increases. The element Sb has negative effect on TRT.     

机械合金化Al-Cu-Fe准晶相形成的研究进展

综述了机械合金化A1-Cu-Fe准晶相的形成机理及热力学稳定性方面的研究进展.     

高强度铸造铝合金细化剂的研制

针对Ａ１－Ｃｕ系高强度铸造合金研制了一种新型盐类晶粒细化剂，使合金晶粒明显细化，机械性能有显著的提高。试验结果表明，该细化剂具有长效性和很强的抗衰退能力，替代中间合金进行细化处理具有操作方便、加入量少和细化效果好等优点，有很高的经济价值。     

三维网络结构增强金属基复合材料的抗压强度模型

利用混合定则和参照Zum-Gahr 模型、Khruschov 模型, 建立了一种连续网络结构增强金属基复合材料的抗压强度模型, 并进一步对模型进行了修正。通过压力和负压浸渗技术制备了不同增强相体积分数的复合材料, 测试了其抗压强度值, 将试验数据与模型进行了拟合, 数据基本在模型限定范围内。形成的相互贯穿、相互缠绕的网络结构增强复合材料的抗压强度与增强相的体积分数在上限时呈线性关系, 且随体积分数的增加而增加; 在下限时呈非线性关系, 当增强相体积分数超过80 %以上时, 抗压强度明显增加。与基体相比, 复合材料的抗压强度有明显提高。      

Processing technique and sliding friction and wear behavior of TiB2／ZA27 composite

In-situ TiB2 particles reinforced ZA27 composite was prepared by the stir-casting technique and a twostep method. TiB2/Al composite was produced by incorporating K2 TiF6, KBF4 salts and other agents into Al melt. As a master alloy, TiB2/Al composite was used to manufacture TiB2/ZA27 composite, which results in the generation of well-distributed reinforcing TiB2 phase. The hardness, friction and wear behavior of TiB2/ZA27 composite were investigated. The results show that the hardness of the composite is enhanced with increasing the content of TiB2 particles, the incorporation of TiB2 reduces the wear rate of TiB2/ZA27 composite and improves the friction property under lubricated and dry sliding friction conditions. The worn track width of ZA27 alloy is 1.6 and 2.5 times as long as that of 2.1%TiB2/ZA27 composite at 150 N and 700 N load under lubricated conditions, which indicates that TiB2/ZA27 composite possesses higher bearing ability.     

原位生成TiB2/ZA27复合材料的制备与性能

以Al熔液为载体,采用原位反应生成形状规则、尺寸细小的TiB₂颗粒相,再将TiB₂颗粒传递到ZA27合金中,形成TiB₂颗粒增强的ZA27复合材料。采用合理的熔炼工艺促进了TiB₂颗粒在基体中的均匀分布。实验结果显示,TiB₂颗粒在ZA27复合材料中,分布均匀,平均直径在3 μm以下。TiB₂颗粒的加入使得复合材料的晶粒明显细化,并随着TiB₂颗粒含量增加,复合材料的抗拉强度、硬度明显提高,2.1%TiB₂/ZA27复合材料与基体合金相比室温抗拉强度提高13%、布氏硬度提高21%,弹性模量也有所提高,在强度、硬度及弹性模量提高的同时,材料的塑性并未恶化,延伸率略有提高,另外,材料的热膨胀系数随着TiB₂颗粒的加入有所降低。     

Effects of Ca addition on microstructure and properties of AZ63 magnesium alloy

1　INTRODUCTIONMg Alalloyshaveaverywideapplicationbecauseoftheirexcellentproperties ,lowmanufacturecost ,easymeltingtechniqueandnoexpensiveele mentscontent[1] .Oneofthiskindalloys ,AZ6 3mag nesiumalloy ,isawidelyappliedmagnesiumsacrifi cialanodewhichisusedextensivelyinundergroundandfreshwateratpresent .However ,compared withthataboard ,homesacrificialanodehassomedemer its :lowcurrentefficiencyandweakprotectionfunc tion ,soinvestigatingthehighdriving potentialandhighefficiencysacrificiala…     

炭材料的高温抗氧化性研究进展

介绍了炭材料的氧化过程,综述了国内外目前提高炭材料抗氧化性能的两个主要途径;基体改性技术和涂层技术。重点阐述了抗氧化涂层的基本要求,涂层的制备方法以及各涂层体系,提出了对于炭材料高温抗氧化性研究方面的一些认识,阐明了其发展前景。     

Na,Sr,Sb,P对铝硅合金致密性的作用

研究了ＺＬ１０１，ＺＬ１０２合金的致密性，考察了Ｎａ、Ｓｒ、Ｓｂ、Ｐ变质元素对合金致密性的影响。试验结果表明，ＺＬ１０２合金有较高的致密性，Ｎａ、Ｓｒ使合金的致密性降低，而Ｐ处理能明显提高合金的致密性。分析认为，致密性与各元素对合金的凝固温度区间的影响有关