杂质元素Fe对铸造铝合金YL102电导率的影响

研究了杂质元素Fe对铸造铝合金YL102电导率的影响。结果表明Si对铸造铝合金电导率产生不利的影响，对电导率要求高的铸件应选用Si的含量较低的铸造铝合金。铸造铝合金YL102中Fe的含量增高会使得铸件的电导率下降，对电导率要求较高的铸件应严格控制原材料中Fe的含量，另外在生产中要采取措施防止铝合金增铁，确保YL102中Fe的质量分数不高于1．0％。     

稀土对铝合金微观组织的影响

研究了添加RE（富铈混合稀土）元素对细晶铝锭及细晶铝锭制造的A356、3003铝合金显微组织的影响。结果发现，RE在铝合金中形成何种化舍物，既与铝合金中所含元素的种类有关，又与RE含量有关；在细晶铝锭中，RE与Fe的交互作用较强，与Si的作用较弱，生成Al-Fe-RE化舍物，但当RE含量超过0．3％时，除形成Al-Fe-RE化舍物外，还形成AlCe3、Al2La；在含硅量较高的T5处理的A356铝合金中，0．3％RE与Mg、Fe的交互作用较弱，与Si的交互作用较强，Ce、La与Si形成CeSi、La5Si3，Mg与Si主要形成Mg2Si；而在含Fe、Mn较高的3003铝合金中，0．3％RE主要生成Al3Ce、LaSi、CeSi2等化舍物，而与Fe、Mn的作用较弱。     

Si、Mg含量对A356铝合金车轮性能的影响

为了研究不同Si、Mg含量对A356铝合金车轮的性能的影响,在经T6处理后的不同Si、Mg含量A356铝合金车轮外轮缘取拉伸试棒,进行力学性能测试,并进行了成品车轮的抗冲击试验和弯曲疲劳试验。试验结果表明:Mg含量变化对合金的性能影响大于Si含量变化;当Si含量为7%、Mg含量为0.32%时,成品车轮的抗冲击性能和抗弯曲疲劳性能最好。     

形变热处理对7A04铝合金组织和性能的影响

采用力学性能测试、金相显微分析和TEM等方法，研究了形变热处理工艺对7A04铝合金的组织和性能的影响。结果表明：形变热处理是使7A04铝合金的塑性和强度同时提高的有效途径。     

稀土Ce对7A04铝合金耐腐蚀性能的影响

目的提高7A04铝合金的耐腐蚀性能。方法采用周期浸润腐蚀试验模拟海洋大气环境,研究了不同稀土Ce含量的7A04铝合金的腐蚀行为及规律。通过金相显微镜和扫描电子显微镜,观察了不同试样的组织和夹杂物形貌。采用失重法和电化学阻抗技术,分析了试样的腐蚀动力学规律及电化学行为特性。结果在Ce质量分数分别为0%、0.39%和0.81%的7A04铝合金中,稀土Ce的加入量为0.39%时,其晶粒最细小,第二相与夹杂最少且分布最均匀,合金的基体组织得到了改善。稀土7A04铝合金的腐蚀失重明显低于不含稀土Ce的7A04铝合金,且锈层电阻升高,其中含0.39%稀土Ce的7A04铝合金的锈层电阻最高。结论三种7A04铝合金均发生了明显的局部腐蚀,主要为点蚀。稀土Ce的加入,改变了非稀土铝合金中的T相和S相,生成了新的细小的块状金属间化合物,改善了组织的均匀性,提高了其腐蚀锈层电阻,增加了锈层对基体的保护能力,使铝合金耐海洋大气腐蚀性能提高。在三种稀土Ce含量的铝合金中,含0.39%稀土Ce的7A04铝合金的耐蚀性最佳。     

套筒类7A04铝合金挤压成形金属流动规律研究

根据等温压缩实验得出7A04铝合金应力一应变数据，拟合出材料温成形应力一应变曲线。应用有限元法模拟7A04铝合金管材的挤压成形，着重探讨7A04铝合金挤压成形过程中，温度、速度等因素对金属流动的影响．为套筒类零件挤压成形工艺提供科学的依据。     

提高7A04铝合金强度的工艺研究

采用深冷技术处理7A04铝合金,通过金相组织分析和力学性能测试,研究了深冷处理对7A04铝合金组织和力学性能的影响.结果表明:采用480℃×80min+120℃×4h深冷+120℃×16h工艺处理后,7A04铝合金的晶粒细化,强度显著提高.     

电脉冲处理对7A04铝合金腐蚀性能的影响

试验研究了电脉冲处理参数对7A04铝合金铸件腐蚀性能的影响。结果表明:电脉冲孕育处理能够使7A04铝合金中初生α-Al晶粒细小圆整,第二相组织分布更加均匀;相同腐蚀周期内,电脉冲孕育处理后试样的蚀坑平均深度和腐蚀面积均小于未经电脉冲处理试样的,7A04铝合金的耐腐蚀性能得到提高。     

形变热处理对7A04铝合金组织和性能的影响

采用力学性能测试、金相显微分析和TEM等方法。研究了形变热处理工艺对7A04铝合金的组织和性能的影响。结果表明：形变热处理是使7A04铝合金的塑性和强度同时提高的有效途径。     

细化剂对高强铝合金半固态浆料组织的影响

研究了细化剂对7A04铝合金大体积半固态浆料组织及其径向均匀性的影响。结果表明,添加晶粒细化元素Zr和Sc可以得到整体平均直径、圆整度分别为46μm、0.63的7A04铝合金半固态浆料组织,并提高大体积浆料组织的均匀性。细化剂作用的7A04铝合金半固态浆料变异系数仅为4.6%,随着温度降低,7A04铝合金半固态浆料组织的尺寸变大,均匀性变差,但圆整度变化不大。     

有害杂质及Ce对8090合金薄板不同加载方向断裂特性的影响

测定了含不同浓度有害杂质及Ｃｅ的８０９０合金薄板不同方向力学性能及断裂性能．结果表明：Ｆｅ，Ｓｉ使各方向的断裂韧性下降，并使４５°方向上的裂纹启裂阻力下降，Ｎａ，Ｋ除对Ｔ－Ｌ方向的启裂阻力不造成明显损害外，能够损害各方向的断裂性能．在合金中添加０．０９％Ｃｅ即可显示有益的合金化作用；如果添加０．２８％Ｃｅ，可明显改善含一定量Ｆｅ，Ｓｉ的合金薄板各方向的断裂性能，其主要原因在于Ｃｅ可通过使再结晶组织均匀，细化晶粒，减少晶界析出相及改善断裂过程等机制抑制杂质对断裂性能的危害．     

Al—Cu—Mg—Si系锻铝合金夹杂相的微观结构

利用Ｘ射线能谱分析和选区电子衍射技术对工业ＡｌＣｕＭｇＳｉ系锻铝合金中粗大夹杂物的成分和结构类型进行了研究     

EFFECTS OF IMPURITIES AND RARE EARTH ADDITION ON THE TOUGHENING LEVELS OF Al-Li BASED ALLOYS 2090 AND 1420

1.IntroductionItispossiblethatbifurcatinganddeflectingduringthecrackpropagationanddelaminatingonthefracturesurfacecancauseanadditionaltougheningbehaviourfortheengineeringmaterials.Theadditionaltougheningbehaviourfromthesefracturepatternsbelongstotheextrinsictougheningscope.Theextrinsictougheningandthenaturaltoughening,ortheintrinsictoughening,arethedecisivefactorsforthetotaltoughenillglevelofthematerials.Ingeneral,thetotaltougheninglevelcanbeobjectivelyreflectedbythematerialfracturetoughness.…     

表面层杂质引起的制备态Fe75Si10B15非晶丝脆性

用扫描电镜、电子探针等仪器，对拉伸断裂的制备态Ｆｅ７５Ｓｉ１０Ｂ１５非晶丝进行了断口和丝的表面分析。分析结果表明：在熔融合金急冷固化期间，合金中尚未熔化的高熔点杂质向丝表面附近的基体层偏聚。在非晶丝表面附近的基体层中存在氧化硅、氧化钙和含碳和硼的化合物杂质。这些高熔点杂质成为非晶丝脆性断裂的裂源，使丝脆化。     

Quantum-mechanical study of effect of lattice defects on surface properties and copper activation of sphalerite surface

The electronic properties of sphalerite (110) surface bearing Fe, Mn and Cd impurities were calculated using density-functional theory, and the effects of impurities on the copper activation of sphalerite were investigated. Calculated results indicate that both Fe and Mn impurities narrow the band gap of sphalerite surface and lead to the Fermi level shifting to conduction band. Impurity levels composed of Fe 3d and Mn 3d orbital appearing in band gap are beneficial to electrons transfer from the valence band to the conduction band and promote the surface conductivity and the electrochemical activity. The results show that Fe and Mn impurities cannot be replaced by Cu atom, which reduces the exchange sites (Zn) for Cu atom, hence Fe- and Mn-bearing sphalerites are hard to be activated by copper. Cd impurity has little effect on electronic structure of sphalerite surface; however, Cd atom is easily replaced by Cu atom, and this is the reason why the Cd-bearing sphalerite can be easily floated.     

杂质及Ce对8090Al—Li合金内,外韧化水平的影响

本文研究了杂质及Ｃｅ对８０９０Ａｌ－Ｎｉ合金内，外韧化水平的影响。结果表明，Ｆｅ，Ｓｉ主Ｎａ，Ｋ杂质有一定外韧化效果，但严重降低内韧化水平，在含料多杂质的材料中添加微量Ｃｅ，能够提高内韧化水平，但却降低外韧化水平。     

温轧工艺对6061铸轧板材显微组织和力学性能影响

采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)及万能拉伸机等研究了不同温轧温度及累积压下率对双辊铸轧6061铝合金板材组织性能的影响。结果表明,6061铝合金铸轧板组织主要由耐热相Al0.7Fe3Si0.3、Al9Fe0.84Mn2.16Si及少量强化相Mg2Si组成。合金中第二相随温轧道次递增逐渐由网格状、片状转变为沿轧制方向的线条状,最终变为细小的颗粒状。温轧后,有新的析出相Al0.5Fe3Si0.5产生,且Mg2Si相的数量增多。6061铝合金铸轧板较为适宜的温轧工艺为:370℃轧制+80%累积压下率,此时铸轧板热处理后的屈服强度、抗拉强度和伸长率分别88.48 MPa,318.76 MPa和20.53%。     

Role of iron in relation to silicon modification in Sr-treated 319 and 356 alloys

The low specific gravity, excellent castability and good corrosion resistance of aluminium—silicon casting alloys makes them important materials for use in automotive applications. The mechanical properties of these alloys are controlled by their chemical composition as well as the quality of their microstructure. To this end, ‘modifiers’ such as sodium, strontium, etc. are normally added to the alloys, whereby large improvements in properties (mainly ductility) are observed, as a result of the ‘modification’ or change in morphology of the Si phase of the Al-Si eutectic from its normally brittle, acicular form to a fibrous form, accompanied by a reduction in the Si particle size. Another important microstructural consideration is control of the iron content in order to minimise the formation of the brittle β-Al₅FeSi phase which, owing to its plate-like nature, is also deleterious to the alloy properties. In view of the fact that Sr modification is normally carried out in Al-Si alloys, and the Fe levels are usually minimised, the present work was carried out determine to what extent the presence of Fe would affect the Si modification in such alloys. Alloys 319 and 356 were selected for study, where the Fe levels in the two alloys were varied from 0·2 to 0·8 and from 0·12 to 0·6 wt-%, respectively, to cover the minimum and maximum limits specified by industry. The effects of Fe and cooling rate (using directional and conventional solidification) on the Si particle characteristics in the unmodified and Sr-modified alloys were studied, using optical and scanning electron microscopy, and quantified using image analysis. Temperature-time parameters of reactions taking place during solidification were determined using thermal analysis. The role of Al₂Si₂Sr precipitation in the Sr-modified alloys is discussed, and a mechanism for the effect of Fe on Si modification in such alloys is also presented. IJCMR/442     

Precipitation of a-Fe from Fe84-xSi4B12+x (x=1,3) Amorphous Alloys Under High Magnetic Field Annealing

This work aims to investigate the effects of high magnetic field annealing (HMFA) on the precipitation of α-Fe from Fe84-xSi4B12+x (x =1,3) amorphous precursors.Isothermal annealing process for Fe81Si4B15 and Fe83Si4B13 amorphous ribbons has been performed with and without the magnetic field.The magnetic field shows the effects of increasing the nucleation rate and decreasing the grain size of α-Fe crystals simultaneously,during the crystallization processes of the investigated amorphous alloys.By applying HMF,α-Fe crystals with more homogeneous distribution and smaller grain size are achieved in the amorphous matrix,which is crucial helpful to improve the magnetic properties for Fe-Si-B amorphous alloys.The mechanism of HMFA affecting the crystallization microstructure is also discussed in the present work.     

原铝中Fe、Si杂质分配系数的计算与测定

通过平衡分配系统的计算,得到原铝中杂质Fe、Si的平衡分配系数（Ko）,通过实验测定了杂质Fe、Si的有效分配系数Ke,实验考察了铝液净化效果。结果表明,铝中的Si和Fe可采用偏析法分离净化,Fe比Si的净化效果更好,这是由于Fe的Ko和Ke比Si的小的原因。