Ti-Cr-V-Al 合金的阻燃机理实验研究

利用激光点火法测定了ＴＣ４合金和Ｔｉ－Ｃｒ－Ｖ－Ａｌ合金的阻燃性能,用Ｘ射线衍射、扫描电镜、Ｘ射线能谱等方法分析了激光点火后两种合金烧蚀坑的表面形貌和成分分布。Ｔｉ－Ｃｒ－Ｖ－Ａｌ合金的阻燃性能明显优于ＴＣ４合金。在Ｔｉ－Ｃｒ－Ｖ－Ａｌ合金烧蚀坑中心区域,铬和钒的含量远低于基体,表明铬和钒的燃烧产物大量以气相形式逸出,与阻燃机理理论分析结果一致。     

一种Cu—Ti—Sn—Cr合金熔炼和铸造的试验研究

本文对Ｃｕ－Ｔｉ－Ｓｎ－Ｃｒ合金熔炼和铸造中的一些关键问题进行了试验研究，得出了适合的工艺参数，为获得优质的Ｃｕ－Ｔｉ－Ｓｎ－Ｃｒ合金锭提供了工艺保证。     

Alloy706燃气轮机部件用ESR钢锭的生产

Ｎｉ基超合金ａｌｌｏｙ７０６添加多种合金元素材料,具有很好的高温特性,但在铸锭时易产生偏析对性能有影响。日本制钢所建立起ＶＩＭ（真空感应熔炼）＋ＥＳＲ（电渣重熔）双联熔炼法。对ＥＳＲ条件进行了研究,已生产出Φ６５０ｍｍ圆钢锭,该合金成分（％）：０．００９Ｃ０．０１Ｓｉ０．０２Ｍｎ４１－６９Ｎｉ１５．７９Ｃｒ１．７０Ｔｉ０．２１Ａｌ０．００３１Ｂ３．０２（Ｎｂ＋Ｔａ）。为防止中心偏析,在ＥＳＲ中研究了熔化速度及其稳定性、渣组成和渣量、电极浸渍深度等。为确保钢锭对通电同轴性,对电接触…     

TiAl合金的制备及应用现状

TiAl合金密度小、高温性能优异,自20世纪50年代以来已发展到第三代。介绍了TiAl合金的性能特点、发展历程,真空感应熔炼、真空自耗电弧熔炼、等离子冷床炉熔炼等熔炼TiAl合金方法的优缺点,以及国内外TiAl合金的制备情况;提出TiAl合金熔炼过程中存在的问题主要是宏观与微观偏析,应从原料加入方式、原料纯度及熔炼工艺等方面进行改进;此外,对TiAl合金在航空航天、汽车工业等领域的应用现状进行了概括,指出TiAl合金近期的研究重点是大尺寸铸锭的均匀化控制。     

钛合金VAR铸锭中的偏析

钛合金铸锭通常都是将海绵钛与合金添加料配合,压制电极块,焊接一次电极,然后二次真空电弧熔炼(简称VAR)而成.该工艺方法本身就存在来自合金元素添加方法引起的偏析和凝固偏析两大弊病.前者一是由于合金元素在电极块中分布不均匀,熔炼中来不及消除就凝固了;二是合金元素中有高熔点和高密度元素,在两次VAR中不能完全熔化和混合均匀.后者是由于电磁力、浮力和重力等因素引起的合金元素集聚而产生的宏观偏析与微观偏析.     

复相高温合金的结构分析

运用电子显微镜、能谱仪以及Ｘ射线衍射仪等分析手段研究了成分为３％Ｃ、３８％Ｎｉ,２８％Ｃｒ、１５％Ｗ、１０％Ｃｏ、６％Ｆｅ的高温合金结构以及合金元素在各相中的分布情况,同时探讨了不同制备方法（真空熔炼和粉末冶金）所形成的合金组织结构的差异。     

技术信息

技术信息国内高钛钛铁真空熔炼开发成功ＴＨＥＳＵＣＣＥＳＳＯＦＰＲＯＤＵＣＩＮＧＨＩＧＨ－ＴｉＦＥＲＲＯＴＩＴＡＮＩＵＭＩＮＶＡＣＵＵＭＩＮＤＵＣＴＩＯＮＦＵＲＮＡＣＥ宝鸡特殊钢厂，拥有大量残钛资源和大型真空感应炉，今年该厂利用真空感应炉熔炼开发成功高...     

大规格TA13钛合金铸锭Cu偏析控制

选用优质海绵钛为原料,以适当规格的Cu屑为合金添加剂,经混料→电极压制→电极焊接→一次真空熔炼→二次惰性气体保护熔炼,得到φ700mm规格TA13钛合金铸锭。分析了大规格TA13钛合金铸锭中Cu元素的分布特点技影响C。偏析的主要因素。合适的原料及配料方式、惰性气体保护电弧熔炼、低熔化速率及合理的补缩工艺等是避免大规格TA13钛合命铸锭中Cu元素发生宏观偏析的重要措施。     

GH2909合金产品局部宏观成分偏析形成原因探讨

通过对GH2909合金宏观成分偏析现象进行宏微观形貌观察、成分分析、重新取样检测及生产过程情况调查,得出：宏观成分偏析是局部的,并产生于真空电弧重熔过程中;由于将电流给定值由6800A提升到7000A,打破了正常重熔瞬间平衡,造成熔速和溶池形状剧烈波动而产生的。     

钛合金棒材热稳定性的分析

众所周知,材料的性能由组织决定,组织由成分决定,成分是否均匀关键在于熔炼.目前,钛合金铸锭的主要生产方法是采用真空自耗电弧二次熔炼,尽管如此,铸锭中还不可避免地存在一些偏析,如间隙元素偏析、合金元素偏析等.铸锭一旦发生偏析,则偏析区的组织与正常区的组织显然不同,当偏析区中的α稳定元素A1或间隙元素     

Ti／Mn基Laves相贮氢合金贮氢性能的影响因素

介绍了影响Ti/Mn基Laves相贮氢合金贮氢性能的一些因素,这些因素包括锆部分取代钛,Cr、V、Fe、Cu、Ni、Co、Mo等元素部分取代锰,非化学计量,非金属杂质元素与杂质气体。同时也介绍了热处理、熔炼方式、氟化处理对Ti/Mn基Laves相贮氢合金贮氢性能的影响。     

Synthesis and Structural Characterization of V–4Ti–4Cr Alloy

V–(4–10)Ti–(4–5)Cr alloys are the potential candidate materials for the high performance structural applications in fusion power systems due to their favorable mechanical and physical properties. In the present study, the alloy design has been attempted through model based approach for pre mentioned composition range. Thermodynamic calculations have been carried out through Miedema model for this alloy system. The enthalpy difference—composition plot for the ternary V–Ti–Cr system indicate the stability of the solid solution phase in this composition range, which is also in agreement with the atomic size variation which is well within the 15 % size variation limit. Based on these plots, an alloy with a composition of V–4Ti–4Cr is considered as the reference composition for our study. The alloys have been prepared by melting the desired compositions of highly pure metals in a water cooled vacuum arc melting unit. For structural information, X-ray diffraction experiment has been carried out. The XRD pattern does not contain any signature for the secondary phase formation. The structure is bcc structure with small variation in lattice parameter from that of pure vanadium. Transmission electron microscopy characterization has also been carried out, which confirms the absence of fine secondary phases and the crystal structure as b.c.c.     

Microstructure and properties of duplex δ-Al3(Ti, V)/β-(Ti, V) alloys

The microstructures of multiphase intermetallic alloys with compositions Al₇₀Ti₁₀V₂₀ and Al₆₂Ti₁₀V₂₈ based on the trialuminide Al₃Ti have been characterized, following chill casting and postsolidification heat treatment, using a combination of scanning electron microscopy and transmission electron microscopy (TEM). Evidence of a eutectic reaction of the form L → δ-Al₃(Ti, V)+ζ-Al₈V₅, not previously reported in the Al-Ti-V system, has been observed in both alloys solidified at sufficient levels of undercooling. The ζ phase is replaced by metallic β-(Ti, V) phase during subsequent heat treatment in the range 1073 to 1273 K, and differential thermal analysis (DTA) of samples prean-nealed at 1173 K revealed an endothermic peak at ∼1560 K, consistent with equilibrium eutectic melting of the form (δ+β) → L. Although the chill-cast alloys retained metastable intermediate high-temperature phases, duplex metallic-intermetallic microstructures, containing uniform fine-scale distributions of metallic β-(Ti, V) solid solution in a δ-Al₃(Ti, V) intermetallic matrix, have been produced in both alloys during isothermal heat treatments at temperatures in the range 1073 to 1273 K. For both alloys, the bulk Vickers hardness of such microstructures remained in excess of that of binary Al₃Ti, while in the Al₆₂Ti₁₀V₂₈ alloy, where the increased volume fraction of β phase took the form of a near-continuous network within δ matrix, there was evidence arising from indentation tests of a substantial improvement in the cracking resistance compared to both chill-cast ternary alloy and binary Al₃Ti.     

Effect of Microstructure on the Creep Properties of Ti–6Al–4V Alloys: An Analysis

The effects of microstructure types and microstructural parameters on creep properties were investigated systematically through an analysis of microstructure and creep properties of Ti–6Al–4V alloys based on the available literature data. The results indicated that the creep properties of the Ti–6Al–4V alloy are strongly dependent on microstructure type. Creep resistance of Ti–6Al–4V alloys is better in lamellar microstructure followed by bimodal and equiaxed microstructure respectively. Also, microstructural parameters such as the size of both prior beta grain and alpha colony and thickness of alpha lamellae in the lamellar microstructure, the volume fraction of primary alpha phase in bimodal microstructure and size of alpha phase in equiaxed microstructure can influence the creep properties.     

急冷对Ti_(0.32)Cr_(0.345)V_(0.25)Fe_(0.03)Mn_(0.055)合金储氢性能的影响

为了研究急冷对储氢合金残余氢量的影响,利用真空电弧熔炼炉和铜模喷铸制备了Ti_(0.32)Cr_(0.345)V_(0.25)Fe_(0.03)Mn_(0.055)合金,采用XRD、PCT(压力-容量-温度)、TG/DTA等手段分析了急冷对储氢合金吸放氢性能的影响。结果表明,铸态合金和急冷合金均由BCC固溶体主相和Laves第二相组成;急冷对首次吸氢动力学行为影响较大,由铸态时的化学反应控制变为急冷时的新相晶核形成长大控制;急冷后,合金吸放氢平台压得到提高,且吸氢起始点左移,但吸放氢滞后性增大。TG/DTA曲线表明,急冷并没有改变合金的残余氢量,但氢化物放氢温度升高。     

Dissolution of iron intermetallics in Al-Si Alloys through nonequilibrium heat treatment

Conventional heat treatment techniques in Al-Si alloys to achieve optimum mechanical properties are limited to precipitation strengthening processes due to the presence of second-phase particles and spheroidization of silicon particles. The iron intermetallic compounds present in the microstructure of these alloys are reported to be stable, and they do not dissolve during conventional (equilibrium) heat treatments. The dissolution behavior of iron intermetallics on nonequilibrium heat treatment has been investigated by means of microstructure and mechanical property studies. The dissolution of iron intermetallics improves with increasing solution temperature. The addition of manganese to the alloy hinders the dissolution of iron intermetallics. Nonequilibrium heat treatment increases the strength properties of high iron alloys until a critical solution temperature is exceeded. Above this temperature, a large amount of liquid phase is formed as a result of interdendritic and grain boundary melting. The optimum solution treatment temperature for Al-6Si-3.5Cu-0.3Mg-lFe alloys is found to be between 515 °C and 520 °C.     

Study on Microstructures of Al-4 wt pct V Master Alloys

Aluminum (Al)-V master alloys have attracted attention, because they can potentially be efficient grain refiners for wrought aluminum alloys. In this paper, the microstructure and factors affecting the microstructure of Al-4 wt pct V master alloys were investigated by means of controlled melting and casting processes followed by structure examination. The results showed that the type and morphology of the V-containing phases in Al-V master alloys were strongly affected by the temperature of the melt, concentration of vanadium in solution in the melt and the cooling conditions. Two main V-containing phases, Al₃V and Al₁₀V, which have different shapes, were found in the alloys prepared by rapid solidification. The Al₃V phase formed when there were both a high temperature (1273 K to 1673 K (1000 °C to 1400 °C)) and a relatively high vanadium content of 3 to 4 wt pct, while the Al₁₀V phase formed at a low temperature (<1373 K (1100 °C)) or a low vanadium content in the range of 1 to 3 wt pct. The results also showed that the type of V-containing phase that formed in the Al-4 wt pct V master alloy was determined by the instantaneous vanadium content.     

Formation of amorphous and metastable extended solid solutions in Cu-Ti alloys using the triode sputtering technique

The triode sputtering technique and a split Cu-Ti target arrangement have been used to produce metastable extended solid solutions and amorphous phases in the Cu-Ti system. Metastable extension of the solid solubility of Ti in Cu-based fcc solid solution of up to 30 at. pct was observed; nearly 20 at. pct of Cu was incorporated metastably into the hcp solid solution based on Ti. Amorphous phase formation was observed in alloys containing approximately between 26 and 84 at. pct Ti. Amorphous deposits were as thick as 250 μm, without the presence of detectable crystalline phases. Interatomic spacings in both crystalline and amorphous alloys were found to follow an approximately linear trend with composition. Microhardness measurements indicated a very substantial increase in hardness in all alloys when compared with an extrapolated linear trend between pure Cu and Ti.     

Multi-dimensional Effect of Heat Treatment on Microstructure and Property of Ti6Al4V Alloy Fabricated by Selective Electron Beam Melting

Metallurgical and Materials Transactions A - The as-built Ti6Al4V component was subjected to a heat treatment of solid solution at 1020&nbsp;°C for 2 hours and followed by aging at...     

稀土钼合金组织结构的研究

在TZM钼合金的基础上，通过复合添加稀土Y、Ce的试验，生产出了高温性能优异且工艺易于控制的钼合金。对不同配方稀土钼合金的组织结构进行了深入分析，指出弥散颗粒不仅存在晶界，也可存在于晶内，因此可同时强化晶界和晶粒，但粗大的弥散颗粒和Mo-Ti固溶体对合金性能不利。用化学法富集了合金中的弥散相，通过X射线衍射和能谱综合分析，确定了弥散相的相结构，证实了在合金中稀土元素Y、Ce与Ti、Zr形成Y2O3结构的复合氧化物。Ti在合金中则有三种可能的存在形态：一是形成复合氧化物，二是形成Ti(C,N),三是形成Mo-Ti固溶体。