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。     

Si、Y对铸造Mg-Zn-Al合金组织性能的影响

研究了Si、Y对Mg-Zn-Al合金显微组织和力学性能的影响。结果表明：Si、Y均能提高合金的抗拉强度和硬度，特别对高温抗拉强度的提高效果更为明显。合金强度的提高主要得益于组织中析出相的弥散强化作用。Mg-6．0Zn-1．5Al-0．15Mn-1．2Si-0．5Y铸造镁合金的显微组织主要由a(Mg)基体、B(MgZn)相、λ(Mg2Si)相和ω(SiY)相组成。     

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.     

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。      

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。     

Mg/Al异种材料真空扩散焊界面区域的显微组织

采用真空扩散焊技术对Mg／Al异种材料进行了焊接。采用金相显微镜、扫描电镜(SEM)、显微硬度计及X射线衍射(XRD)对扩散界面附近的显微组织及性能进行了试验研究。试验结果表明，Mg／Al异种材料真空扩散焊在加热温度Tp=450-490℃，压力强度P=0．08-0．10MPa，保温时间t=40-60min时能得到良好的扩散焊接头。扩散焊界面过渡区形成了致密的新相化合物层，断口形貌呈粗糙暗灰色，以解理断裂为主并伴有脆性的混合型断口，扩散界面过渡区生成了MgAl、Mg3Al2、Mg2Al3等金属间化合物。     

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…