TiO2对镁合金废旧料组织性能的影响

利用等离子发射光谱仪、金相分析、电镜、岛津材料试验机等方法研究了含TiO2的熔剂对镁合金废旧料的力学性能、组织、断口形貌的影响。研究发现，对于AZ91镁合金废旧料，使用含TiO2的熔剂除了可以有效清除镁熔体中夹杂物外，还可将镁废旧料中的Fe含量降到0.0056%以下。试验结果表明，TiO2有助于使γ相成粒状或小岛状析出，并具有较强的细化晶粒的效果。采用含TiO2的熔剂净化处理后的AZ91镁合金废旧料的σb和δ可分别达到188.5MPa和4.13%，其性能达到了AZ91新料的水平。金相观察结果表明，净化处理对断口形貌无明显影响，不改变AZ91镁合金断裂机理，断口均成准解理断裂。     

TiO2与MnCl2对Mg合金旧料组织性能的影响

测试了含有不同量的TiO2或MnCl2的熔剂对Mg合金废旧料的力学性能、组织、断口形貌以及腐蚀行为的影响．结果表明，TiO2和MnCl2均可以降低Mg合金废旧料中的Fe含量，TiO2的除Fle效果可达0．0053％以下，优于MnCl2的效果．通过降低Fe量可以提高试样的σb和δ，MnCl2的效果优于TiO2．采用含30％TiO2或MnCl2的熔剂对Mg合金废旧料进行净化处理后，其σb和δ可分别大于185．3MPa和3．71％，即达到了AZ91Mg合金新料的性能指标．研究还表明，Ti02或MnCl2加入量一定时，均可以提高Mg合金的耐蚀性．但当熔剂中MnCl2的含量高于30％时，Mg合金的耐蚀性反而下降．Ti02有助于使γ相成粒状或小岛状析出，并具有很好的细化晶粒的效果．     

Mn含量对Mg-Mn阳极显微组织和电化学性能的影响

采用高纯镁为原料制备高效Mg-Mn牺牲阳极,探讨了Mn含量分别为0.3%、0.6%、0.8%、1.0%时,对Mg-Mn牺牲阳极显微组织和电化学性能的影响.结果表明,Mn能够有效降低镁熔体中Fe的含量,提高镁阳极的电流效率,但过多的Mn能够和Si、C、O形成相对于α-Mg基体的少量阴极相,加重镁阳极的自腐蚀,使镁阳极的电流效率降低,不同Mn含量的Mg-Mn阳极基体组织均为α-Mg固溶体,Mn含量较低时组织为粗大的柱状晶,增大Mn的含量组织为等轴晶,继续增大Mn含量晶粒细化不明显.     

杂质元素对Al-Zn-In-Mg-Ti牺牲阳极电化学性能的影响

采用Al-Zn-In-Mg-Ti合金作为阳极材料,杂质元素分别为Fe、Si和Cu,通过控制变量法,对牺牲阳极进行电化学性能测试。讨论了杂质元素对Al-Zn-In-Mg-Ti牺牲阳极电化学性能和表面溶解状态的影响。评价了不同杂质元素对Al-Zn-In-Mg-Ti牺牲阳极腐蚀防护性能的影响。结果表明:当Fe元素含量控制在0.1%左右,Si元素含量控制在0.1%左右,Cu元素含量控制在0%的情况下,Al-Zn-In-Mg-Ti牺牲阳极腐蚀防护性能最佳。     

镁含量对铝阳极材料组织和电化学性能的影响

运用合金相电化学原理，向铝中添加合金元素镁，制备成Al-Mg二元合金，试验研究了镁含量对铝合金阳极材料组织与电化学性能的影响。结果表明，合金中Mg5Al8相随镁含量增加而增加且分布均匀。组织组成物的阳极性能良好，在浓度为3．5％的NaCl介质中，当w（Mg）从1％提高至30％时，进入稳定状态的开路电位从-0．79V负移至-1．18V，阳极极化率亦降低。     

高电位镁合金牺牲阳极生产过程控制与研究

论述了高电位Mg-Mn牺牲阳极材料的组织结构,电化学性能以及应用。重点分析研究了杂质Fe、Ni、Cu、Si、Al等元素对其自腐蚀机理,Mn成分及相关组织、熔铸工艺控制对高电位镁阳极组织和电化学性能的影响,指出高电位镁阳极生产过程存在的有关问题并对其未来发展趋势进行展望。     

纯Mg熔体净化工艺与纯镁阳极电化学性能研究

采用粗Mg直接精炼熔铸的短流程工艺制备了纯Mg牺牲阳极。在硅热还原法炼Mg的还原罐中设置结晶器过滤器净化粗Mg,精炼过程中采用低压转注提纯、分层加热精炼的新工艺净化Mg熔体,并分析净化机理。结果表明,结晶过滤器直接捕获含杂质相的氧化物降低Ni、Si、Fe元素含量,并建立结晶温度梯度使Al先于Mg结晶,降低Al的含量;低压转注和分层加热提纯能够有效减少Mg熔体夹杂物。电化学性能测试表明,纯Mg阳极电流效率和开路电位均高于高电位Mg阳极的行业标准。     

专利信息（Ⅰ）

本发明属于金属材料领域，特别涉及一种制备金属间化合物基软磁材料——含硼，钛，锆，矾的Fe3Si基合金超薄板的方法。薄板中Fe含量为92％，93％，Si含量为6％，7％。其特征在于合金中加入了0．02％，0．58％的硼和0．5％，1％的Ti，Zr和V。工艺控制上采用铸锭退火、控制锻造、热轧、热轧板退火等措施，利用传统的锻造与轧制设备成功制备出厚度为0．10，0．30mm的Fe3Si基合金薄板。     

Fe-Si合金系熔体结构的X射线衍射研究

利用X射线衍射仪，在1550℃研究了从纯Fe到纯Si共14个成分的合金熔体的结构，所选取合金包括某些在固态时的金属间化合物或有序固溶体，成分间隔大约为10％Si(原子分数)．通过对结构因子第一峰高度、位置及其半高宽、偶相关函数第一峰位置、径向分布函数第一峰形状以及配位数等随成分变化的分析，认为Fe-Si合金系的熔体结构在整个成分范围内可以分成4个区间。它们的边界分别为纯Fe，Fe0.754Si0.246，Fe0.50Si0.50，Fe0.282Si0.718和纯Si，在边界合金的两边，结构呈现明显差别．液态Feo．50Sio．50合金的结构保留了一些金属间化合物FeSi的特征。当Si含量大于50．0％时，Fe-Si合金熔体中开始出现Si-Si共价键．对其他研究者所使用的模型和结论进行了讨论．     

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。     

Purification technology of AZ91 magnesium alloy wastes

1　INTRODUCTIONBecausemagnesiumalloyhastheadvantagesoflowdensity ,highspecificstrengthandrigidity ,ex cellentdampingeffect,goodtolerancetoimpact ,ex cellentmachinabilityandpolishingability[1,2 ] ,itiswidelyusedinthefieldsofautomobilemanufactur ing ,aviationandspaceflight,communication ,opticinstrumentsandcomputermanufacturing[35] .How ever ,theyieldofmagnesiumalloyislowinthepro ductionofdiecasting .Atpresent ,theutilizationra tiocanonlybeabout 30 % 5 0 % .Intheprocessofdiecasting ,alargeq…     

Characterization and photocatalytic activity for methylene blue degradation of iron-deposited TiO2 photocatalyst

Iron-deposited TiO2 was prepared by photo-reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO2 was deposited with iron, and the optimum n(Fe)/n(Ti) is 0. 25%. TiO2 and iron-deposited TiO2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, theXRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe^3 and Fe^2 are present on the surface of 0.5% iron-deposited TiO2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe^3 /Fe^2 couple seems plausible, but Fe^2 can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO2, because iron deposited traps photo-generated electrons and holes. The fluorescence intensity order of TiO2 and iron-deposited TiO2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO2 and iron-deposited TiO2, from low to high.     

快淬Fe—Cr—Mo—Si—B非晶合金中的相分离

透射电镜观察到非晶Ｆｅ６５Ｃｒ１８Ｍｏ２Ｓｉ１Ｂ１４和Ｆｅ６２Ｃｒ１８Ｍｏ２Ｓｉ１ｂ１７基体中分布着纳米级颗粒状的非晶第二相。磁测量与Ｍｏｓｓｂａｕｅｒ谱显示出非晶样品由少量铁磁相与顺磁基体相组成，并表现出单畴颗粒的高矫顽力。快淬过程中这冷液体里硼的偏聚导致非晶合金中非晶第二相的形成及脆化。     

Microstructure and hot cracking susceptibility of high conductivity Al–Fe–Si alloys

Aluminium–silicon based casting alloys have been extensively utilised in various industrial applications, but their relatively low electrical and thermal conductivities make them unsuitable for high conductivity parts. In this research, Al–Fe–Si based high conductivity alloys containing limited silicon content were investigated. Al–0·5Fe–xSi alloys with silicon ranging from 0·5 to 2% showed significantly higher electrical conductivity than conventional Al–Si based alloys. The hot cracking susceptibility of Al–Fe–Si alloys became seriously high as the Si content increased up to 1·5%, then susceptibility rapidly reduced with the further increase in Si. The relationship between solidification characteristics and hot cracking susceptibility of Al–0·5Fe–xSi alloys was discussed based on the thermal and cooling curve analyses and microstructural observations.     

Effects of silicocalcium on microstructure and properties of Mg-6Al-0.5Mn alloy

1 Introduction Magnesium alloys are attractive for applications in the automobile, aerospace and electronic industries due to their light mass, high stiffness, high specific strength, good dimensional stability and damping capacity. It is the lightest sp…     

Influence of Mg additions on solidification and performance of B206-type aluminum castings of high Fe and Si contents

The role of magnesium content, which varies from 0.2 to 0.6% (% by mass), and of high iron and silicon concentrations (Fe≈0.3%, Si≈0.3%) in B206 aluminum alloys were studied. Microhardness measurements were performed on samples prepared from fractured tensile specimens that were served for microstructural characterization as well. The results of mechanical testing showed that the properties are highly influenced by the iron to silicon ratio and the nominal concentration of magnesium. The best properties were obtained for investigated alloys of low iron and silicon concentrations with a ratio close to one, in agreement with results obtained by solidification study. The addition of magnesium, in specific amount, leads to an increase in the 0.2% elastic stress and without significant effect on the microhardness of alloys studied.     

增强颗粒对镁基复合材料磨损性能的影响(英文)

研究增强颗粒Mg2Si对镁基复合材料摩擦磨损性能的影响,讨论Si加入量、载荷和滑动速度对Mg2Si/AM60镁基复合材料磨损性能的影响。结果表明,向镁合金中加入合金元素Si,可原位生成增强颗粒Mg2Si,增强颗粒Mg2Si可明显提高AM60镁合金的磨损性能。随着载荷和滑动速度的增加,AM60镁合金和Mg2Si/AM60镁基复合材料的磨损量都增大。AM60镁合金的磨损机制为粘着磨损。随着载荷的增大,Mg2Si/AM60镁基复合材料的磨损由磨粒磨损向粘着磨损转变。     

Influence of phosphorus on oxidation behavior of low thermal expansion superalloy IN909 at 650℃

The effect of phosphorus on the oxidation resistance of low thermal expansion alloy IN909 was studied. The composition and structure of the oxidation layer were analyzed. It is found that the oxidation initiates at the grain boundaries. During the oxidation, Fe atoms diffuse toward the surface and form the outside oxidation layer as the oxide of iron. The transition oxidation layer lies between the oxidation layer and the matrix which is enriched with Nb, Ti and Si, forming FeTiO5, Nb2O5, Fe2SiO4 and TiO2. Phosphorus hardly influences the thermal expansion coefficient of IN909 alloy. However, it increases the formation of e phase at the boundary of the transition oxidation layer and matrix. As a result, the oxidation rate is decreased efficiently because the e phase inhibits the diffusion of the element such as iron from the matrix to the oxidation layer.     

Comparison of corrosion behaviors of AZ31, AZ91, AM60 and ZK60 magnesium alloys

The corrosion behaviours of four kinds of rolled magnesium alloys of AZ31, AZ91, AM60 and ZK60 were studied in 1 mol/L sodium chloride solution. The results of EIS and potentiodynamic polarization show that the corrosion resistance of the four materials is ranked as ZK60＞AM60＞AZ31＞AZ91. The corrosion processes of the four magnesium alloys were also analyzed by SEM and energy dispersive spectroscopy(EDS). The results show that the corrosion patterns of the four alloys are localized corrosion and the galvanic couples formed by the second phase particles and the matrix are the main source of the localized corrosion of magnesium alloys. The corrosion resistance of the different magnesium alloys has direct relationship with the concentration of alloying elements and microstructure of magnesium alloys. The ratio of the β phase in AZ91 is higher than that in AZ31 and the β phase can form micro-galvanic cell with the alloy matrix, as a result, the corrosion resistance of AZ31 will be higher than AZ91. The manganese element in AM60 magnesium alloy can form the second phase particle of AlMnFe, which can reduce the Fe content in magnesium alloy matrix, purifying the microstructure of alloy, as a result, the corrosion resistance of AM60 is improved. However, due to the more noble galvanic couples of AlMnFe and matrix, the microscopic corrosion morphology of AM60 is more localized. The zirconium element in ZK60 magnesium alloy can refine grain, form stable compounds with Fe and Si, and purify the composition of alloy, which results in the good corrosion resistance of ZK60 magnesium alloy.