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块体非晶合金是一类具有高强度、高硬度和大弹性极限的无序金属材料,其优异的力学性能是目前先进金属材料领域研究热点之一,如何提高材料的强度是材料研究领域永恒的主题。系统地总结了已知具有超高强度的一类块体非晶合金材料——钴基块体非晶合金的成分、热学稳定性及力学性能;同时研究了不同非晶合金的断裂强度与其弹性常数、硬度和特征温度的关联。研究结果表明:在非晶合金体系中杨氏模量、维氏硬度、玻璃转变温度与断裂强度之间都存在较好的线性变化关系。基于以上结果,本课题组提出了超高强钴基块体非晶合金的组成设计方法,即选取具有强共价键特性的非金属元素和高模量、高熔点过渡金属元素与钴元素进行组合。 相似文献
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Fe基和Co基非晶合金具有优越的软磁特性 ,已广泛用在电源器件、磁头和各种传感器等方面。为了更加广泛地利用这种材料 ,当前人们正在积极研究利用粉末冶金法等制作块体非晶材料的可能性 ,但因非晶粉末的变形能太小以致难以获取具有良好软磁性的块体材料。近年来发现Mg基、Zr基、Ln基 (稀土系 )等许多合金系具有很宽大的晶化温度 (Tx)前的过冷液相区 (ΔTx=Tx-Tg,Tg 是玻璃转化点 )。这些合金在ΔTx 温度区粘性急剧降低 ,并且显示出理想的超塑性变形 ,可望具有优良的二次加工性。日本东北大学金属材料研究所和アルプス… 相似文献
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利用熔体粘度测试、X射线衍射分析、高温DSC分析等方法,研究了Al84Mg10Ce6合金的熔体粘度随温度变化的规律,结合薄带的非晶形成能力,分析了合金熔体不同过热温度与其非晶形成能力的相关性.结果表明,Ce元素的加入使得Al84Mg10Ce6熔体产生了结构突变,增强了铝基合金非晶形成能力,Al-Mg系合金非晶形成能力与其熔体温度之间具有相关性,850 ℃熔体通过熔甩工艺制得非晶态薄带. 相似文献
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通过铜模铸造法制备出了具有异质结构的Zr63Ni16.2Cu15.8Al5和Zr63.4Ni16.2Cu15.4Al5块体非晶合金.利用X射线衍射(XRD)和差示扫描量热法(DSC)研究了两种Zr基块体非晶合金的微观结构和热稳定性,采用动电位极化方法研究了两种Zr基块体非晶合金在NaCl水溶液中的耐腐蚀性能.结果表明,与均匀结构的Zr65Al10Ni10Cu15块体非晶合金相比,异质结构降低了材料的热稳定性以及耐腐蚀性能,耐腐蚀性能低的原因可能是由于微观结构的不均匀使其具有更多的界面引起的. 相似文献
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通过铜模铸造法制备了具有异质结构的Zr64.2Ni16.2Cu14.6Al5和Zr63.4Ni16.2Cu15.4Al5块体非晶合金,利用X射线衍射(XRD)、高分辨透射电镜(HRTEM)和差示扫描量热法(DSC)研究了其微观结构及热稳定性。结果表明,与均匀结构的Zr65Al10Ni10Cu15块体非晶合金相比,异质结构降低了材料的热稳定性。在单轴压缩试验中,两种Zr基块体非晶合金具有大的塑性应变(>25%)和高的屈服强度(>1.6GPa)。低的STZs势能和高的剪切带扩展抗力是异质结构Zr基块体非晶合金塑性提高的主要原因。 相似文献
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Thermodynamics, kinetics and structural relaxation of Ce-based bulk metallic glass-forming liquid were investigated in the glass transition region by calorimetric measurements. The differences in thermodynamic functions were calculated between the supercooled liquid and crystalline state of the Ce-based alloys. Structural relaxation was studied by heating rate dependence of glass transition temperature. In terms of fragility parameter m, the Ce-based alloys were stronger liquid than other metallic glass-forming liquids. The correlation of the excellent glass-forming ability of Ce-based alloys with the thermodynamic property (Gibbs free energy) and the kinetic property (m) was discussed. The structural relaxation from glass state to the equilibrium supercooled state was well described by Tool-Narayanaswamy-Moynihan (TNM) model using the parameters derived from the calorimetric measurements. 相似文献
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1 INTRODUCTIONMetallicglassisregardedasastatethatisofdis orderunlikecrystalalloyswith periodicatomstruc ture.Soitshowsexcellentcapabilitiesofsoftmag netism ,mechanics ,corrosionresistance ,etc .How ever ,mostofamorphousalloyswereproducedbyus ingrapidsolidificationmethodssuchassplatquench ing ,meltspinning ,andsoon ,withcharacteristiccoolingratesof 10 4 10 6 K/s .Becauseamorphousal loysarepreparedwithsilk ,powderandribbon ,itisgreatlylimitedinengineeringapplication .Recently ,severalbulk… 相似文献
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采用磁悬浮熔炼和Cu模吸铸工艺成功制备了圆棒Cu50Zr42Al8块体非晶合金,试样表面平滑且具有典型的金属光泽。试验制备的圆棒Cu50Zr42Al8块体非晶合金的直径尺寸小于Ф5mm,该成分的块体非晶合金具有较强的非晶形成能力,其玻璃转变温度Tg=723K,晶化温度t=773K,过冷度△T=50K,约化玻璃转变温度Trg=0.753。 相似文献
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镁基大块非晶合金在深过冷液相区的塑性变形 总被引:1,自引:3,他引:1
研究了Mg65Cu25Y7Nd3大块非晶合金在玻璃转化温度Tg附近及深过冷液相区的等温压缩变形行为。结果表明,Mg65Cu25Y7Nd3大块非晶合金的塑性变形与加热温度和加载时间紧密相关。在423K时该大块非晶合金具有一定的塑性,而在深过冷液相区则具有良好的塑性。通过系列试验,得出了Mg65Cu25Y7Nd3大块非晶合金的最佳加热温度为443~463K,加载时间约10min。对大块非晶合金在变形过程中的结构变化的分析表明,在本试验条件下,压缩变形对Mg65Cu25Y7Nd3大块非晶合金的晶化过程没有明显的影响。 相似文献
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《Intermetallics》2000,8(5-6):499-501
During the past 10 years, research about bulk amorphous alloys has made some progress and a great quantity of data has been published. One of the main studying aims is to find a series of alloys with high glass-forming ability so they can be fabricated by conventional casting or high-pressure die casting techniques. However, traditional “trial and error’’ methods have still been used to explore new bulk amorphous alloy systems. It is time to design bulk amorphous alloy compositions by computer aided design referring to condensed state physics, computational materials science and database. A database has been assembled with a lot of documents and data about bulk amorphous alloys. It has convenient inquiry, index, and modification functions. In the database, disorder data have been systemized and regularized, and can be directly used by other computational programs. It concluded that the bulk amorphous alloys database is especially helpful to research and design bulk amorphous alloys. 相似文献
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Bulk amorphous metal—An emerging engineering material 总被引:1,自引:0,他引:1
During the last two decades, researchers have developed families of metal alloys that exhibit exceptional resistance to crystallization
in the undercooled liquid state. Upon cooling, these alloys readily form glass or vitrify to form bulk amorphous alloys or
bulk metallic glasses. The stability of the undercooled molten alloys with respect to crystallization has enabled studies
of liquid thermodynamics, rheology, atomic diffusion, and the glass transition previously not possible in metallic systems.
Bulk amorphous alloys exhibit very high strength, specific strength, and elastic strain limit, along with unusual combinations
of other engineering properties. These factors, taken together, suggest that bulk amorphous metals will become widely used
engineering materials during the next decade. 相似文献
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