Nd对块体Mg-Cu-Y-Nd非晶合金玻璃形成能力的影响

在非真空熔炼条件下采用工业纯原材料和负压铜模吸铸法制备Mg65Cu25Y10-xNdx(x=0,2,4,6,8,10)棒状试样,利用差示扫描量热(DSC)和X射线衍射(XRD)等方法分析Nd对Mg-Cu-Y-Nd非晶合金玻璃形成能力的影响。结果表明:Nd的含量(x)为0,4,6成分的合金试样具有完全非晶态组织,且x=4时具有最大的玻璃形成能力,其约化玻璃转变温度(Trg)为0.592,过冷液相区宽度(ΔTx)高达66 K;当x为2,8,10时,由于合金成分明显偏离共晶成分,玻璃形成能力降低,试样只含有少量非晶,且主要呈晶体组织特征。     

Y元素添加对CuZrAl块体金属玻璃的结构和力学性能的影响(英文)

研究添加Y元素对CuZrAl块体金属玻璃的结构和力学性能的影响。结果表明,添加Y元素提高CuZrAl体系的玻璃形成能力,而且由于添加Y元素可以降低该体系的结合能,从而降低其断裂强度。Cu45Zr48Al7块体金属玻璃的断裂表面主要呈脉状,而Cu46Zr42Al7Y5块体金属玻璃的断裂表面则很平滑。TEM观察表明,Cu45Zr48Al7的微观结构为非晶基体中含有纳米相,然而Cu46Zr42Al7Y5块体金属玻璃为全非晶结构。     

Be对Al-La-Ni合金玻璃形成能力的影响(英文)

铍是半径最小的金属元素,它在锆基、钛基及其他很多种合金体系中显示出非常重要的作用,极大的提高了合金的非晶形成能力。基于这些特点,我们将铍引入铝基非晶合金,在AlLaNi合金中加入不同比例的铍(1at%～10at%),通过X射线衍射仪,扫描电镜,差热分析仪等研究合金的显微结构和铍对合金非晶形成能力及热力学参数的影响。结果显示1at%到5at%的铍的添加,提高了合金的玻璃形成能力,其中含有1at%铍的合金具有最高的玻璃形成能力及高的热稳定性。     

Crystallization of Mg-based bulk metallic glass

1 Introduction Since INOUE et al[1,2] reported that amorphousalloy with the composition of Mg65Cu25Y10 could beproduced with thickness up to 4 mm by conventionamold casting technique, Mg-based bulk metallic glasses(BMGs) have been proposed as a new kind …     

合金相的“团簇+连接原子”模型与成分设计

以最近邻配位多面体为基元描述复杂合金相的结构特征,总结出合金相的常见团簇类型,并建立了合金相的团簇+连接原子模型。以此为基础解析准晶和非晶合金为代表的团簇合金的结构与团簇成分式特征,提出复杂合金相成分设计的团簇式方法,并以块体非晶合金和稳定固溶体合金为例说明多组元合金相团簇成分式的建立与运用过程以及团簇基元及连接原子种类与数目的确定原则。前期研究工作表明,基于团簇+连接原子模型的团簇成分式方法为多元复杂合金相定量设计提供了新的有效途径。     

Ti基大块金属玻璃的研究与应用

阐述了Ti基大块金属玻璃(BMG)的成分设计原则及制备方法，并对Ti基非晶合金及其部分晶化复合材料的力学性能及断裂机理进行了评述。结果表明：Ti基大块金属玻璃具有较高的断裂强度、弹性延伸率及一定的塑性延伸率，而经过部分晶化获得的非晶合金基纳米颗粒复合材料，其室温塑性获得很大的改善。在此基础上探讨了该合金目前所存在的问题、研究热点以及其应用前景。     

Phases in the crystallization process of Zr_(65)Al_(7.5)Ni_(10)Cu_(17.5)metallic glass

The crystallization process of metallic glass Zr65Al7.5Ni10Cu17.5, (atom fraction in %) were studied by transmission electron microscopy and X-ray diffraction. Two stages of crystallization process, which are indicated by the two exothermic peaks in the differential scanning calorimetry diagram, were studied separately. It is found that the phases in the various stage of the crystallization are different, In the first stage, it consists mainly of tI-CuZr2 and tP-Al2Zr3 phases, between which a definite orientation relationship is found. While in the second stage, in addition to the above phases, phase hP2-Al2NiZr6 and phase hP3-α-Zr appear, between which another orientation relationship is also found. At the same time, a comparison is made based on the study of the phases exist in the arc-melted master ingot. The lattice parameters of the identified phases were determined and some interesting similarities were found. According to these similarities, all the phases were classified into two groups. The fi     

Micro-forming characteristics of a Zr-based amorphous alloy with a gear-like mold

The amorphous alloy Zr₆₂Cu₁₇Ni₁₃Al₈ exhibits a supercooled liquid state over a wide temperature range under high temperatures. In this present paper, the authors studied the micro-forming ability of the alloy by compressing specimens under a miniature pattern mold with a micro-gear shape. Micro-compressive formation is a formation method in which the surface of specimens of the Zr₆₂Cu₁₇Ni₁₃Al₈ amorphous alloy is compressed under conditions of dead loads and high temperatures and maintained for a given period for the fabrication of miniature patterns with a micro-gear shape. All the experiments were carried out under a vacuum environment to prevent the specimens from suffering deleterious effects, such as air traps in the miniature patterns and oxidation at the surface of the Zr₆₂Cu₁₇Ni₁₃Al₈ amorphous alloy. The characteristics of micro-compressive formation were investigated at temperatures higher than the glass transition temperature with different experimental parameters of loads and times. In addition, the micro-forming characteristics of the gear-like shape were investigated by means of scanning electron microscopes and a 3-D surface profiler system.     

通过制备非晶涂覆钢丝提高钢丝抗腐蚀性能

为了提高钢丝的耐腐蚀性能,使用连续涂覆工艺制备一系列锆基非晶合金(Zr41.2Ti13.8Cu12.5Ni10Be22.5)100-xNbx (x=0, 3, 5, 8 at. %)涂覆Q195钢丝。相分析结果表明涂层主要由非晶基体和一些金属间化合物组成;阳极极化实验发现所有非晶涂覆钢丝表现钝化行为,具有高的点蚀破钝电位和低的腐蚀电流。随着非晶涂层中铌含量增加,非晶涂覆钢丝的钝化区宽度增加,点蚀破钝电位升高。电子能谱分析发现,非晶涂覆钢丝抗点蚀性能提升可能与金属铌元素容易钝化,形成稳定钝化膜,同时能够稳定锆、钛,降低相分离有关。     

Effect of cold rolling on glass transition of Zr_(55)Al_(10)Ni_5Cu_(30) bulk metallic glass

Zr55Al10Ni5Cu30 bulk metallic glass was prepared through water-cooled copper mold suction casting, and was rolled up to 95% in thickness reduction. The structures and thermal stabilities of the as-cast and as-rolled specimens were examined by X-ray diffractometer and differential scanning calorimeter. As the thickness reduction increases, the crystallization onset temperature, peak temperature and the apparent activation energy of crystallization almost keep constant, while the glass transition temperature decreases from 681 to 671 K and the apparent activation energy of glass transition increases from (404±26) to (471±29) kJ/mol. The glass transition process is markedly affected by the rolling induced changes of microstructure and structural relaxation.     

Thermal stability and mechanical properties of Gd-Co-A1 bulk glass alloys

The glass forming ability of Gd-Co-A1 ternary alloy systems with a composition ranging from 50% to 70% （molar fraction） for Gd and from 5% to 40% （molar fraction） for AI were investigated by copper mold casting and Gd60Co25Al15 bulk glass alloy cylinders with the maximum diameter of 5 mm were obtained. The reduced glass transformation temperature （TG/Tm） and the distance of supercooling region ATx are 0.616 and 45 K, respectively for this Gd-Co-A1 alloy. The compressive fracture strength （σf） and elastic modulus （E） of Gd-Co-A1 glassy alloys are 1 170-1 380 MPa and 59-70 GPa, respectively. The Gd-AI-Co bulk glassy alloys with high glass forming ability and good mechanical properties are promising for the future development as a new type function materials.     

Zr-Al-Ni-Fe块体非晶合金的成分设计与优化

以等电子浓度和等原子尺寸为判据,以Zr-Al-Ni-Fe合金系为研究体系,设计并制备了7种电子浓度和平均原子尺寸相等但成分不同的系列块体合金.XRD结果表明,只有靠近Zr-Al-Ni三元系的4个合金得到块体非晶;DSC和DTA结果表明,这4个合金中的最佳成分,即具有最高玻璃形成能力和最好热稳定性的合金是Zr60 7Al15.5Ni15.5Fe8.3,其特征热力学参数Tg=710 K,Tx=770 K,△Tx=60 K,Tg/Tm=0.607,Tg/Tl=0.552.     

新型铜基块体非晶合金Cu55-xZr37Ti8Inx的制备及性能

利用铜模吸铸法合成Cu—ZrTi—In非晶棒。块体非晶合金Cu50Zr37Ti8In5的△瓦值最大,为66K。从原子尺寸大小和热力学角度分析在铜基非晶合金中添加适量In元素后能够提高其非晶形成能力的原因。在所测的块体非晶合金Cu55．Zr37Ti8Inx（x≤〈5）,Cu52Zr37Ti8In3表现出最高的抗压强度（1981MPa）和最佳的塑性,其在压缩断裂前的总塑性变形量约为1．2％。     

Amorphous-crystalline transition layers formation during quenching of Fe61Co7Zr10Mo5W2B15melt

New Fe-based multicomponent amorphous alloys have been developed recently based on empirical rules for large glass forming ability(GFA).In the present investigation,the master alloy ingot with the nominal composition of Fe61Co7Zr10Mo5W2B15(mole fraction,%)was prepared by arc-melting under Ti-gettered Ar atmosphere. The Fe-based uttons with different transverse cross sections were fabricated by arc-melting method,and the d2.5mm Fe-based rods were manufactured by injection technique.Characterization of the ingots and the parameters associated with the thermal stability were carried out by X-ray diffractometry(XRD)and high temperature differential scanning calorimeter(DSC),respectively.The interval of the supercooled liquid region is 39K for the Fe-based alloy.The GFA of Fe-based alloys is relatively lower,to the buttons obtained are all crystallized.The Fe-based rod exhibites a high Vickers hardness up to HV 1329.In addition,and amorphous-crystalline transition layers are observed in the rod.This transition zone is caused by unhomogeneous temperature distribution and relatively lower GFA for Fe-based alloys.     

Zr-Al-Co块状非晶的成分优化

运用等电子浓度和变电子浓度线判据实现了Zr—Al—Co块状非晶合金的成分优化．在(Al50Co50)-Zr等电子浓度线(e／α=1．5)和(Zr9Co4)—Al及(Zr78．5Co21．5)—Al变电子浓度线上设计成分，并通过吸铸法制备块状合金．实验结果表明，在(Al50Co50)—Zr等电子浓度线和(Zr9Co4)—Al变电子浓度线上可形成块状非晶合金，且非晶合金的热稳定性与非晶形成能力随电子浓度的增大而单调递增．其中，(Al50Co50)-Zr等电子浓度线和(Zr9Co4)—Al变电子浓度线交点处形成的Zr53Al23．5Co23．5非晶合金，具有最大的热稳定性和非晶形成能力，特征热力学参数Tg=783K，Tx=849K，Tg／Tm=0．637，Tg／Ti=0．590。     

大块金属玻璃基复合材料制备技术研究进展

介绍了国内外几种制备大块金属玻璃基复合材料的方法和形成的组织，阐明了组织中增强相对力学性能的影响，展望了大块金属玻璃基复合材料的发展趋势。     

Sc提高锆基块体非晶合金玻璃形成能力的机理

以Zr52.5Cu17.9Ni14.6Al10Ti5五元锆基非晶合金为研究对象，在以工业级海绵锆为原料制备的合金中加入元素Sc，制备出楔形试样，从微观角度分析了元素Sc提高非晶合金玻璃形成能力的机理。结果表明，元素Sc的加入可显著改变Zr52.5Cu17.9Ni14.6Al10Ti5五元锆基块体非晶态合金在非晶态-晶态过渡区中先析相的相结构及组织形态。元素Sc强烈的脱氧作用可减少合金中锆氧化物／锆氧团簇，从而消除了过冷液体中异质形核的核心，提高了Zr52.5Cu17.9Ni14.6Al10Ti5五元锆基块体非晶态合金的玻璃形成能力。     

热处理对铜基大块金属玻璃晶化过程的影响

利用差热分析仪（DSC）和X射线衍射仪（XRD）等研究了不同热处理方法对Cu60Zr20Hf10Ti10大块金属玻璃晶化过程的影响。结果表明,在698K退火1h,铜基大块金属玻璃的晶化激活能明显降低;在过冷液相区等温晶化时,随温度降低,晶化的孕育时间和过程都明显延长;不同温度下淬火处理对随后晶化过程影响很大。     

非晶及纳米结构钛合金研究进展

综述了钛基大块非晶的成分-非晶形成能力的对应关系，总结了已知的钛基大块非晶的一次结晶相及力学性能，并阐述了钛基大块非晶的塑性变形机制，以及造成低塑性的因素和改善塑性的方法，着重介绍了铸造纳米结构钛合金的成分、组织和力学性能。通过精巧的成分设计，结合金属模铸造技术，制备出了直径小于5mm，并具有微米尺度β-Ti（M）一次树枝晶相＋纳米尺度棒状β-Ti／γ-TiCu共晶结构的复合组织，其中棒状β-Ti相尺寸在30nm～300nm范围；γ-TiCu共晶基体相由小于10nm的晶粒或亚晶粒组成，这种多层次纳米结构的钛合金具有高强度，同时县有明显的延伸性。