Observation of a metastable aluminide ThFe2Al10

Metastable ThFe₂Al₁₀ ternary aluminide was observed in the as-cast Al-6.1at.%Th-6.1at.%Fe alloy. It crystallizes into an orthorhombic structure belonging to Pmmn space group symmetry and possesses unit cell with parameters a = 9.076 Å, b = 8.998 Å and c = 5.031 Å.The ThFe₂Al₁₀ (Pmmn) phase can be considered as a metastable state of the equilibrium ThFe₂Al₁₀ (Cmcm) compound; its formation should be directly related to the cooling rate of the alloy during casting. After annealing the as-cast alloy at 600 °C for one week the metastable ThFe₂Al₁₀ (Pmmn) phase decomposes: the particles of this phase are no longer observed in SEM, and the diffraction peaks associated with this phase disappear in the XRD pattern.     

Zn-10Al合金超塑变形的研究

用恒载荷蠕变法研究了Ｚｎ１０Ａｌ合金的超塑变形特性,测定了Ｚｎ１０Ａｌ合金的应变速率敏感指数ｍ值和超塑变形激活能Ｑ值。     

DRY SLIDING WEAR OF PM Al 10Ti ALLOY

１ＩＮＴＲＯＤＵＣＴＩＯＮＤｕｒｉｎｇｄｒｙｓｌｉｄｉｎｇｏｆｔｈｅａｌｕｍｉｎｕｍａｌｏｙｓａｎｄａｌｕｍｉｎｕｍｍａｔｒｉｘｃｏｍｐｏｓｉｔｅｓａｇａｉｎｓｔｓｔｅｅｌｓ,ｔｈｅｒｅｅｘｉｓｔｔｗｏｄｉｓｔｉｎｃｔｗｅａｒｒｅｇｉｍｅｓ,ｉ．ｅ．...     

Nd60Al10Fe20Co10金属玻璃的变形行为

利用材料测试系统(MTS)、X-Ray衍射(XRD)和扫描电镜(SEM)等手段研究了Nd基大块金属玻璃的变形行为和断裂特征.Nd基大块金属玻璃样品在室温下是脆性断裂,大约在500 K时变形模式从非均匀变形转变为均匀变形,在523 K以上表现出显著的塑性变形.在5×10-4 m/s的应变速率下,这种Nd基大块金属玻璃材料在523 K～600 K之间出现明显的屈服应力下降现象,随后进入1种稳定的粘性流动状态,而且这种屈服下降现象与温度和应变速率有关.这种在过冷液相区的变形行为与其他大块金属玻璃变形特征相似.合金的这种塑性变形行为表明了其存在稳定的过冷液相区,同时对其变形行为的研究有助于进一步了解Nd基大块金属玻璃的反常热稳定性.     

Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15合金的非晶和晶态薄带吸氢行为研究

研究两种不同成分具有较大过冷液相区的四元合金Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15，非晶和晶态薄带吸氢行为，结果表qt两种薄带的吸氢量均随着温度的升高而增大，非晶薄带的吸氢量要小于同等条件下的晶态薄带的吸氢量且只有在673K吸氢后形成了氢化物，Zr65Al7.5Ni10Cu17.5非晶和晶态薄带吸氢后分别生成了Zr2NiH4.7和ZrH2；而Zr65Al10Ni10Cu15非晶和晶态两种薄带最后生成的氢化物同为ZrH2。     

Zr65Al10Ni10Cu15非晶合金电阻率的研究

在不同加热速率下利用恒流四电极法研究了非晶合金Zr65Al10Ni10Cu15的电阻率随温度的变化情况,根据电阻率随温度的变化情况可以把晶化前的温度区间分为3个阶段,第一和第二阶段分别对应于低温结构弛豫和高温度结构弛豫发生的温度区间,而第三阶段的变化情况与前二个阶段明显不同,并在晶化前出现电阻率极大值峰。研究表明,利用电阻率随温度的变化情况,可以反映出非晶更多的结构转变的信息。     

Nd_(60)Al_(15)Cu_(10)Co_(10)Fe_5大块非晶态合金的制备

采用铜模浇铸法制得直径４．０ｍｍ、长６０ｍｍ圆柱状Ｎｄ６０Ａｌ１５Ｃｕ１０Ｃｏ１０Ｆｅ５大块非晶样品。样品的非晶性经Ｘ射线衍射（ＸＲＤ）实验检验证实。采用示差扫描热分析（ＤＳＣ）、Ｘ射线衍射分析了非晶合金的晶化过程。Ｎｄ６０Ａｌ１５Ｃｕ１０Ｃｏ１０Ｆｅ５非晶态合金的约化玻璃温度Ｔｒｇ＝０．６０,说明合金有较好的非晶形成能力。采用Ｋｉｓｓｉｎｇｅｒ方法求得非晶态合金的表观晶化激活能。根据熔化焓对Ｎｄ６０Ａｌ１５Ｃｕ１０Ｃｏ１０Ｆｅ５合金深过冷液相与稳定晶相间的吉布斯自由能差进行了估算。结果表明,Ｎｄ６０Ａｌ１５Ｃｕ１０Ｃｏ１０Ｆｅ５合金深过冷液相与稳定晶相间的吉布斯自由能差,ΔＧ,在过冷液相区小于２ｋＪ／ｍｏｌ,表明过冷液相的晶化驱动力很小,过冷液相区内的晶相形核具有较大的热垒。     

OXIDATION OF PM ALLOY Al-10Ti DURING SLIDING WEAR

ＯＸＩＤＡＴＩＯＮＯＦＰＭＡＬＬＯＹＡｌ１０ＴｉＤＵＲＩＮＧＳＬＩＤＩＮＧＷＥＡＲ①ＷｕＮｉａｎｑｉａｎｇ，ＷａｎｇＧｕａｎｇｘｉｎ，ＬｉＺｈｉｚｈａｎｇＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｚｈｅｊ...     

RECRYSTALLIZATION IN Ti-10V-2Fe-3Al ALLOY

<正> Ti-10V-2Fe-3Al合金是七十年代问世的高强高韧近β钛合金。本文从金相和真应力-真应变曲线两个方面研究该合金在热变形过程中及随后冷却过程中的再结晶特性。     

B对铸造Pb-Mg-10Al合金摩擦磨损性能的影响

利用立式高频感应炉制备出3组不同B含量的铸造Pb-Mg-10Al合金,并对其摩擦磨损性能进行了研究.采用X射线衍射仪分析物相,用扫描电镜观察其显微组织.结果表明,随着B的添加,合金组织中出现了陶瓷相AlB2颗粒,由于陶瓷相的增多,合金的硬度得到显著提高.室温滑动摩擦磨损试验表明,合金的耐磨性能随B含量的增加而增加,当B含量为2％时,其磨损量和摩擦因数最小.     

Coarsening mechanisms in a dendritic Al–10% Cu alloy

Coarsening of a dendritic Al–10 wt.% Cu alloy at 570 °C was investigated by fast in situ X-ray tomography. The variation of the specific solid–liquid interface area as a function of time was found to follow a power-law relation with an exponent close to ?1/4. Three coarsening mechanisms operate in the alloy: (i) melting of small dendrite arms to the benefit of the adjacent arms (small arm melting), similar to Ostwald ripening; (ii) gradual movement of the base of the interdendritic grooves towards the tips (interdendritic groove advancement); (iii) coalescence of dendrites near the tips leading to the entrapment of liquid tubes or droplets (coalescence and groove advancement). The coarsening models proposed in the literature do not adequately resemble or predict the behaviour observed in the experiments. New models were developed for the first two coarsening mechanisms and predict the coarsening rate with very good agreement.     

Cu-60Ni-10Al和Cu-60Ni-15Al三元合金在800℃的高温氧化行为

研究了Cu-60Ni-10Al和Cu-60Ni-15Al（at％）在800℃的氧化行为。2种合金在初始阶段氧化较快，但与相应的Cu-Ni二元合金相比，铝的存在使合金的氧化速率大为降低；随着完整的保护性Al2O3层形成，合金的氧化速率进一步降低。氧化24h后，Cu-60Ni-10Al氧化膜外层仍有铜镍氧化物存在，10at％Al不足以使合金得到完全保护；而Cu-60Ni-15Al氧化膜完全由Al2O3层组成。对于60at％Ni的Cu-Ni-Al三元合金，获得完全保护的最佳铝浓度在10at％～15at％之间。     

Oxide formation on sputtered Ni-3Cr-10Al nanocrystalline coating

1　ＩＮＴＲＯＤＵＣＴＩＯＮＮａｎｏｃｒｙｓｔａｌｌｉｎｅｃｏａｔｉｎｇｓｃｏｕｌｄｂｅｐｒｏｄｕｃｅｄｂｙｍａｇｎｅｔｒｏｎｓｐｕｔｔｅｒｔｅｃｈｎｉｑｕｅｏｎｔｈｅｓｕｂｓｔｒａｔｅｓｏｆｔｈｅｓａｍｅｍａｔｅｒｉａｌｓａｎｄｅｘｈｉｂｉｔｅｄｇｏｏｄｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅｒｅｓｕｌｔｅｄｆｒｏｍｔｈｅｐｒｏｍｏｔｉｏｎｏｆｔｈｅｓｅｌｅｃｔｉｖｅｏｘｉｄａｔｉｏｎｏｆＡｌａｎｄｔｈｅｆｏｒｍａｔｉｏｎｏｆａｕｎｉｔａｒｙｌａｙｅｒｏｆＡｌ2Ｏ3ｅｖｅｎｗｉｔｈｌｏｗＡｌｃｏｎ…     

Zr60Al10Ni30非晶合金的吸氢特性

非晶合金已广泛用于电源铁芯、磁头、各种传感器、电力变压器以及磁屏蔽等许多领域中。近年来又发现了许多过冷液相区很宽的非晶合金,这些非晶合金的临界冷却速度小,有可能制得尺寸较大的非晶合金,可望作为新型工业材料获得广泛应用。这些合金的特征是自玻璃转变温度(Ｔｇ)到晶化温度(Ｔｘ)的范围内熔体粘度显著降低,随着粘度的变化其它物性也会发生很大变化。当今所使用的贮氢合金几乎都是晶态金属合金,然而晶态贮氢合金经过反复的吸放氢循环之后往往发生微粉化问题,如果制成非晶态贮氢合金这种微粉化问题就可得到缓解。但是,随着贮氢合金…     

TiC_p对Zn-10Al合金凝固行为的影响

利用XDTM 法与搅拌铸造技术相结合的工艺制备了TiCp/Zn 10Al(% )复合材料 ,采用定向凝固技术研究增强粒子TiCp 在凝固界面的行为及对复合材料凝固速度的影响。结果表明 :TiC颗粒被凝固的界面前沿所排斥 ,造成界面前沿TiC颗粒富集 ,但当TiC颗粒含量超过 6 %后 ,富集现象已不显著。同时发现随着TiC颗粒含量的增加 ,复合材料的凝固速度降低。     

Crystallization kinetics of amorphous Zr65Cu25Al10 alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｇｌａｓｓｆｏｒｍｉｎｇ ｍｕｌｔｉｃｏｍｐｏ ｎｅｎｔａｌｌｏｙｓｙｓｔｅｍｓｗｉｔｈｖｅｒｙｌｏｗｃｒｉｔｉｃａｌｃｏｏｌｉｎｇｒａｔｅｓｗｉｔｈｉｎ 1～ 10 0Ｋ/ｓｈａｓｏｆｆｅｒｅｄｆｉｒｓｔ     

纳米晶Al88Ce2Ni10铝合金的形成

通过晶化法，可以将快凝Ａｌ８８Ｃｅ２Ｎｉ１０非晶铝合金制备成纳米晶合金。纳米晶合金的组织为αＡｌ固溶体和金属间化合物Ａｌ３Ｎｉ及Ａｌ１１Ｃｅ３组成的多相纳米晶结构。在６０３～７７３Ｋ较宽退火温区内，用Ｓｃｈｅｒｅｒ公式计算各晶化相，得到αＡｌ、Ａｌ３Ｎｉ及Ａｌ１１Ｃｅ３的晶粒尺寸分别为３１～３１６、２２～２０７及１９～１６５ｎｍ。结果表明，通过控制热处理条件，可以获得不同晶粒尺寸的纳米晶合金。其中获得晶粒细小、结构均匀超细纳米晶合金的最佳退火温度为第二ＤＳＣ峰值温度附近     

High-strain-rate superplasticity of Zr65Al10Ni10Cu15 sheet fabricated by squeeze casting method

The Zr₆₅Al₁₀Ni₁₀Cu₁₅ alloy sheet produced by squeeze copper-mold casting method exhibited excellent superplasticity (a maximum elongation of 1350%) at a relatively high strain rate (2×10^–2s^–1) at 696 K. This achievement was made despite the occurrence of crystallization in the middle of deformation. Time for the onset of strain hardening could be related to the T.T.T. diagram for crystallization. Effect of holding time on flow stress was examined. As the holding time was longer, strain hardening took place earlier and the resulted fracture strain was smaller. Bulging test showed that the Zr₆₅Al₁₀Ni₁₀Cu₁₅ alloy sheet could be deformed to near-net-shape by avoiding crystallization when fast heating rate and short holding time were applied.     

Embrittlement of Ti-Al alloys in the 6 to 10 Pct Al range

Ti-Al binary alloys in the range from 6 to 10 pct Al have been found to become embrittled due to the occurrence of a second phase. The degree of embrittlement appears to depend upon the following factors: aluminum content, aging temperature and time, rate of deformation, and testing temperature. Debye powder pattern lines for the second phase are in agreement with the Ti₂-Al phase reported by Ence and Margolin.