Cu,Fe元素含量对喷射成形Al_(98-3x)Cu_(2x)Fe_xNi_1Ce_(0.5)Zr_(0.5)合金组织和性能的影响

采用喷射成形技术制备了不同成分的Ａｌ９８ － ３ ｘＣｕ２ ｘＦｅｘＮｉ１Ｃｅ０ ．５Ｚｒ０ ．５（ 摩尔分数, ％ ） 合金快速凝固材料。重点研究了Ｃｕ , Ｆｅ 元素含量对合金微观组织、力学性能以及断裂机制的影响。研究结果表明, ｘ ＜ ２ 时, 可有效避免粗大的Ａｌ７Ｃｕ２Ｆｅ 平衡相形成; ｘ ＝ １ ．５ 时, 合金具有较好的综合力学性能,合金的抗拉强度、屈服强度、延伸率和弹性模量分别可达６４３ ＭＰａ ,５５８ ．４ ＭＰａ ,８ ．４ ％ 和８０ ．４ ＧＰａ 。     

Fe-Cu-Nb-Si-B纳米晶合金结构的Mssbauer谱研究SCIEI

测定了Ｆｅ_（７３．５）Ｃｕ_１Ｎｂ_３Ｓｉ_（１３．５）Ｂ_９合金的单辊快淬制备态条带及其经热处理后的室温透射Ｍｓｓｂａｕｅｒ谱．制备态谱为典型非晶展宽六线谱，其内磁场平均值Ｈｉ＝１７．０１ＭＡ／ｍ．在Ｎ_２气氛保护下经４８０℃退火０．５ｈ已有明显结构弛豫或部分晶化发生；５３０℃退火１ｈ后样品已显著晶化，其主要组成为α－Ｆｅ（Ｓｉ）固溶体纳米晶和剩余非晶相，后者约占３９．１％，并随退火温度升高而减少，至６２０℃退火后约为２５％．非晶相的Ｈｉ值在结构弛豫阶段稍有上升，而在显著晶化温度以上则随温度升高而减小．在５５０℃退火样品中存在不同取向的体相磁织构．     

Fe-Cu-Nb-Si-B纳米晶合金结构的Mssbauer谱研究

测定了Ｆｅ_（７３．５）Ｃｕ_１Ｎｂ_３Ｓｉ_（１３．５）Ｂ_９合金的单辊快淬制备态条带及其经热处理后的室温透射Ｍｓｓｂａｕｅｒ谱．制备态谱为典型非晶展宽六线谱，其内磁场平均值Ｈｉ＝１７．０１ＭＡ／ｍ．在Ｎ_２气氛保护下经４８０℃退火０．５ｈ已有明显结构弛豫或部分晶化发生；５３０℃退火１ｈ后样品已显著晶化，其主要组成为α－Ｆｅ（Ｓｉ）固溶体纳米晶和剩余非晶相，后者约占３９．１％，并随退火温度升高而减少，至６２０℃退火后约为２５％．非晶相的Ｈｉ值在结构弛豫阶段稍有上升，而在显著晶化温度以上则随温度升高而减小．在５５０℃退火样品中存在不同取向的体相磁织构．     

STRUCTURAL STUDY OF NANOCRYSTALLINE Fe-Cu-Nb-Si-B ALLOYS BY MSSBAUER SPECTROSCOPY

测定了Ｆｅ_（７３．５）Ｃｕ_１Ｎｂ_３Ｓｉ_（１３．５）Ｂ_９合金的单辊快淬制备态条带及其经热处理后的室温透射Ｍｓｓｂａｕｅｒ谱．制备态谱为典型非晶展宽六线谱，其内磁场平均值Ｈｉ＝１７．０１ＭＡ／ｍ．在Ｎ_２气氛保护下经４８０℃退火０．５ｈ已有明显结构弛豫或部分晶化发生；５３０℃退火１ｈ后样品已显著晶化，其主要组成为α－Ｆｅ（Ｓｉ）固溶体纳米晶和剩余非晶相，后者约占３９．１％，并随退火温度升高而减少，至６２０℃退火后约为２５％．非晶相的Ｈｉ值在结构弛豫阶段稍有上升，而在显著晶化温度以上则随温度升高而减小．在５５０℃退火样品中存在不同取向的体相磁织构．     

铝硅钛多元合金在柴油机活塞中的应用

用铝矿直接除铁电解工艺生产的铝硅钛多元合金，其主要成分为铝、硅（３％～１０％）和钛（０．４％～２．０％），此外，还有总量为０．１％的Ｋ、Ｖ、Ｇａ、ＲＥ、Ｎａ和Ｃａ等多种微量元素。用铝硅钛多元合金直接熔配的铸造铝－硅合金，具有良好的耐热性和耐磨性。用这种合金浇注的活塞，其本体强度σｂ＝２２９～２４４．７ＭＰａ，σｂ＾３００℃＝９５．５Ｍｐａ，体积稳定性≤０．０２５％，均优于常用活塞合金ＺＬ１０８、６     

氧含量及过热度对铸态Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_5大体积玻璃合金微观组织结构及力学性能的影响

利用射流成型法制备了厚度为２ｍｍ的Ｚｒ５２．５Ｃｕ１７．９Ｎｉ１４．６Ａｌ１０Ｔｉ５金属玻璃薄板,通过控制氧含量和过热度来改变 玻璃薄板中淬态结晶相的体积分数。研究表明：低的氧含量水平和高的过热度有利于提高该合金的玻璃形成能力,形 成完全非晶的合金;完全非晶的 ２ｍｍＺｒ５２．５Ｃｕ１７．９Ｎｉ１４．６Ａｌ１０Ｔｉ５大体积金属玻璃薄板其断裂应力为 １７１０ＭＰＳ,弹性模量为 ８０ＧＰａ,弹塑性为２．２％。提高合金中的氧含量水平或者降低熔体过热度都有利于结晶相析出。基体中出现２％和６％的结晶相时,断裂应力分别降为１５８ＭＰａ和１２２０ＭＰａ．淬态结晶相的析出改变了Ｚｒ５２．５Ｃｕ１７．９Ｎｉ１４．６Ａｌ１０Ｔｉ５大体积金属玻 璃剪切流变的变形方式,使材料脆断。     

ZrAlCuNiNb合金的非晶形成能力及性能

用X射线衍射(XRD)与示差扫描量热仪(DSC)研究了添加Nb元素对Zr57Al15-xCu15.4Ni12.6Nbx合金的非晶形成能力的影响以及冷却速率对非晶形成的影响，同时研究了形成的块体非晶合金以及热处理后的压缩性能。结果表明：当Nb的摩尔分数达到5％时(即Zr57Al15-xCu15.4Ni12.6Nbx5)，合金具有最强的非晶形成能力，该块体非晶合金的压缩强度达1705MPa，相对压缩率约为0．104％。热处理后，当非晶合金中出现分离相或晶化析出相时，压缩强度将急剧下降。     

Fe73.5Cu1Nb3Si13.5B9非晶合金电脉冲处理与等温退火的比较

用直流高密度电脉总和可比等温退火处理Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９非晶合金,并用ＸＲＤ,ＴＥＭ和穆斯堡尔谱方法进行了结构检测。结果表明,在电脉冲作用下,Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｐ９非晶合金在平均温度为４２０℃的条件下发生了纳米晶化,晶化度试样中无Ｆｅ－Ｂ相析出,无ＤＯ３型有序结构;晶化总量达３０．９％的无序ａ－Ｆｅ（Ｓｉ）相的平均尺寸为８～９ｎｍ,按二项式分布计算ａ－Ｆｅ（Ｓ     

FeCuNbSiB合金的纳米晶化过程研究

应用Ｘ射线衍射分析和穆斯堡尔谱学研究了Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９非晶合金的纳米晶化过程．Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９合金在５００～６００℃温度范围内分别退火１ｈ，可形成纳米ＤＯ３结构的ＦｅＳｉ相和剩余非晶相。随着退火温度的升高，有更多的ＦｅＳｉ相析出。在５００℃等温退火中ＦｅＣｕＮｂＳｉＢ合金出现二阶段纳米晶化过程。     

热处理对Hf-基非晶合金力学性能的影响

采用铜模浇铸法制备Hf44.5Cu27Ni13.5Ti5Al10块体非晶合金,并对其进行等温退火处理。利用X射线衍射仪（XRD）和透射电镜（TEM）对非晶合金的晶化行为进行了分析,并通过MTS810实验机及场发射扫描电子显微镜（FESEM）研究了等温退火对合金力学性能的影响。结果表明,该非晶合金等温退火相转变进程为：非晶→非晶＋Al16 Hf6Ni7→非晶＋Al16 Hf6Ni7＋CuTi2→CuHf2＋CuTi2。合金断裂强度随退火温度的升高先增大后减小。743 K等温退火后,合金断裂强度达到最大值2400 MPa,弹性应变为3.0%。在Hf44.5Cu27Ni13.5Ti5Al10块体非晶合金压缩断口上观察到纳米级韧窝及周期性条纹结构。随着退火温度的升高,周期性条纹间距逐渐减小直至消失,断口形貌呈现为脆性解理断裂的河流状花样。     

Microstructure and Mechanical Properties of Mg–7.4% Al Alloy Matrix Composites Reinforced by Nanocrystalline Al–Ca Intermetallic Particles

Mg–7.6% Al(in mass fraction) alloy matrix composites reinforced with different volume fractions of nanocrystalline Al3Ca8 particles were synthesized by powder metallurgy,and the effect of the volume fraction of reinforcement on the mechanical properties was studied.Room temperature compression test reveals considerable improvement on mechanical properties as compared to unreinforced matrix.The compressive strength increases from 683 MPa for unreinforced alloy matrix to about 767 and 823 MPa for the samples having 20 and 40 vol% of reinforcement,respectively,while retaining appreciable plastic deformation ranging between 12 and 24%.The specific strength of the composites increased significantly,demonstrating the effectiveness of the low-density Al3Ca8 reinforcement.     

Role of nanocrystals on the plasticity of amorphous alloy

The role of nancocrystals on the plasticity of the Cu₆₄Zr₃₆ amorphous alloy was studied in terms of the initiation of shear bands and the propagation of cracks. The plastic deformation behaviors of the fully amorphous and the partially crystallized samples with various degrees of crystallinity were compared. The partially crystallized alloys with an adequate amount of nanocrystals showed a considerable enhancement in their plasticity. Finite element calculations were conducted to qualitatively examine the role of the nanocrystals on the formation of the shear bands, while high-resolution electron microscopy was used to directly observe the crack propagation behavior through the matrix with (or without) nanocrystals.     

Crystallization and microstructure evolution of amorphous Al85Y4Nd4Ni7 alloy

The mixture model of Al85Y4Nd4Ni7 alloy in which a partially crystallized amorphous alloy is regarded as a nanocomposite of an Al nanoparticle and a remaining amorphous matrix is presented. Its evolution in the process of crystallization has been investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Mainly amorphous structure with α-Al nanocrystals embedded in the amorphous matrix has been revealed by melt spining the alloy. Crystallization is showed to occur in three stages: (I) crystallization of amorphous alloy and formation of A1NiY, A1NdNi and unknown crystalline phases, (2) formation of Al3Y and Al3Nd, and (3) formation of Al3Ni.     

Development of High Strength Ni–Cu–Zr–Ti–Si–Sn In-Situ Bulk Metallic Glass Composites Reinforced by Hard B2 Phase

In the present study, the influence of atomic ratio of Zr to Ti on the microstructure and mechanical properties of Ni–Cu–Zr–Ti–Si–Sn alloys is investigated. The alloys were designed by fine replacement of Ti for Zr from Ni₃₉Cu₂₀Zr_36?xTi_xSi₂Sn₃. The increase of Ti content enhances glass forming ability of the alloy by suppression of formation of (Ni, Cu)₁₀(Zr, Ti)₇ phase during solidification. With further increasing Ti content up to 24 at.%, the B2 phase is introduced in the amorphous matrix with a small amount of B19′ phase from alloy melt. The bulk metallic glass composite containing B2 phase with a volume fraction of ~ 10 vol% exhibits higher fracture strength (~ 2.5 GPa) than that of monolithic bulk metallic glass (~ 2.3 GPa). This improvement is associated to the individual mechanical characteristics of the B2 phase and amorphous matrix. The B2 phase exhibits higher hardness and modulus than those of amorphous matrix as well as effective stress accommodation up to the higher stress level than the yield strength of amorphous matrix. The large stress accommodation capacity of the hard B2 phase plays an important factor to improve the mechanical properties of in situ Ni-based bulk metallic glass composites.     

Zr55Al10Ni5Cu30块状非晶合金靠近玻璃转变点的等温纳米晶化

研究了Zr55Al10Ni5Cu30块状非晶合金靠近玻璃转变点等温晶化过程。结果表明：420℃退火5h,出现了尺寸为20nm左右的晶相,同时,非晶基体也出现了尺寸为1－2nm分布均匀的团簇状结构;退火10h,析出的晶相尺寸为20－50nm,所占的体积分数为40％;退火20h之后,非晶相完全转变为亚稳相,析出的晶相尺寸为50nm左右,并没有出现明显的长大现象。退火得到的晶相为Cu10Zr7,Zr2Ni及一些未能标定的相,这些相在420℃具有相对的稳定性,没有问题稳定相转变。退火后,残余非晶相的热稳定性降低。等温退火过程经历了从非晶相→团簇状结构→亚稳相的转变过程。     

Crystallization kinetics of amorphous Zr65Cu25Al10 alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｇｌａｓｓｆｏｒｍｉｎｇ ｍｕｌｔｉｃｏｍｐｏ ｎｅｎｔａｌｌｏｙｓｙｓｔｅｍｓｗｉｔｈｖｅｒｙｌｏｗｃｒｉｔｉｃａｌｃｏｏｌｉｎｇｒａｔｅｓｗｉｔｈｉｎ 1～ 10 0Ｋ/ｓｈａｓｏｆｆｅｒｅｄｆｉｒｓｔ     

Microstructure and magnetic properties of electrodeposited Gd-Co alloy films

Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The elec- troreduction of Co2 and Gd3 was investigated by cyclic voltammetry. The reduction of Co2 is an irreversible process. Gd3 cannot be re- duced alone, but it can be inductively co-deposited with Co2 . Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer (ICPES), and the microstructure was observed by scanning electron micrograph (SEM). The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrat- ing sample magnetometer (VSM). The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. More- over, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.     

Nanostructured bulk glassy Cu_(60)Zr_(30)Ti_(10) alloy with high strength and good ductility in cast state

1　INTRODUCTIONSinceaseriesofmetallicbulkglassyalloyswithexpectedmechanicalpropertiesandhighglassformingabilityhavebeenfound[13] ,particularattemptshavebeendonetoimprovethemechanicalpropertiesoftheglassyalloystomeetengineeringapplications .Bycrystallizingthemetallicglasses ,nanostructuredal loyscontainingnanocrystallinephasesandglassyma trixwereobtainedandthemechanicalpropertiesofthealloyswereenhancedbyhomogeneousdispersionofnanoscalemetallic particlesintheAl [4 ,5] ,Fe Ni [6 ] andMg [7]…     

Effect of annealing on microstructure and mechanical property of a Ti–Zr–Cu–Pd bulk metallic glass

The crystallization behavior and mechanical properties of Ti₄₀Zr₁₀Cu₃₆Pd₁₄ bulk metallic glass were investigated. Nano-composites consisting of glassy matrix are formed in the alloys annealed at 693 and 723 K. After annealing at 823 K, the residual glass is completely crystallized. High yield strength of over 2100 MPa and distinct plastic strain of 0.8% are obtained in the nano-composite alloy annealed at 693 K. The compressive strength decreases for the alloys annealed at higher temperatures of 723 and 823 K, accompanying with the progress of crystallization. The alloy rods both in as-cast and annealed (at 693 K for 10 min) states show the fracture surfaces consisting of vein pattern. On the other hand, the fracture morphology of the alloys annealed at 723 and 823 K changes to brittle character with flat facets.     

放电等离子烧结-非晶晶化法合成Ti7oNb7.8Cu8.4Ni7.2Al6.6复合材料

采用机械合金化制备不含和含2%(体积分数)B4C的钛基非晶合金粉末,随后采用放电等离子烧结-非晶晶化法合成不含／含(TiB+TiC)的Ti7oNb7.8Cu8.4Ni7.2Al6.6超细晶／细晶钛基复合材料;运用X射线衍射分析(XRD)、差示扫描量热分析(DSC)、扫描电子显微镜(SEM)和万能材料试验机等对制备的钛基非晶粉末和超细晶／细晶钛基复合材料进行表征.结果表明高能球磨80h的钛基粉末中主要为非晶相,B4C颗粒的加入对钛基粉末的玻璃转变温度、晶化温度和晶化焓有显著的影响.另外,不含／含(TiB+TiC)的复合材料的显微硬度分别为5.47和5.33GPa;以50K/min升温到1223K并保温10min获得的Ti70Nb7.8Cu8.4Ni7.2Al6.6块体试样的断裂强度和断裂应变分别为2098MPa和11.5%.