锰对Ti—45Al—10Nb合金的组织和性能的影响

研究了Ｍｎ对Ｔｉ－４５Ａｌ－１０Ｎｂ（原子分数）合金铸态组织和１１００℃再结晶组织的影响以及Ｍｎ对于Ｔｉ－４５Ａｌ－１０Ｎｂ合金力学性能的影响。结果表明，Ｍｎ能促进Ｔｉ－４５Ａｌ－１０Ｎｂ合金的再结晶过程，并改善合金的力学性能。     

复相Al3Ti—8Mn基合金的显微组织

在Ａｌ－Ｔｉ－Ｎｂ－８Ｍｎ四元系邻近Ｌ１２型Ａｌ３Ｔｉ－８Ｍｎ成份区合金中,随Ｎｂ含量变化,其显微组织发生明显变化。通过对不同合金的微观组织的考察,进一步确认了在Ａｌ６７Ｍｎ８Ｔｉ２５基金中加Ｎｂ并相应调整Ａｌ和Ｔｉ含量可形成ＤＯ２２型Ａｌ３（Ｔｉ,Ｎｂ）,Ｌ１０型ＴｉＡｌ和Ｇａ２Ｈｆ型Ａｌ２Ｔｉ３种类型的第二相。本文列举了Ａｌ６７Ｍｎ８ｔＩ２３Ｎｂ２,Ａｌ６５Ｍｎ８Ｔｉ２６－５Ｎｂ０．５,Ａｌ５     

氢化Ti－25Al－10Nb－3V－1Mo铸态合金的热压缩行为及其显微组织

利用等温热压缩方法在９００－１０００℃范围内，研究了氢化对Ｔｉ３Ａｌ基的Ｔｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１Ｍｏ合金热变形行为的影响，并分析了显微组织的变化氢为０．２％（质量分数，下同）的试样可使峰值流变应力比未氢化试样降低３７％－４５％，即相当于降低热压缩温度约５０℃。氢化促进合金的α２相动态再结晶、球化及β相的动态回复     

变形及热处理对Ti－45Al－10Nb－0．1Y合金组织与性能的影响

探讨了通过等温锻造及热处理改善Ｔｉ－４５Ａｌ－１０Ｎｂ－０１Ｙ显微组织，提高其室温塑性的途径。论述了合金力学性能与显微组织的关系。     

Ti—47Al—2Mn—2Nb合金低温静态和动态拉伸性能及硼的影响

采用常规拉伸和Ｈｏｐｋｉｎｓｏｎ拉杆技术,研究具有近全片层组织形变Ｔｉ－４７Ａｌ－２Ｍｎ－２Ｎｂ合金１８０Ｋ下静态和动态拉伸性能及其受硼的影响。发现Ｔｉ－４７Ａｌ－２Ｍｎ－２Ｎｂ和Ｔｉ－４７Ａｌ－２Ｍｎ－２Ｎｂ－１Ｂ合金１８０Ｋ下的拉伸强度均比室温度。     

T45Al10Nb附带 金全片层组织韧脆转变机制的研究

研究了应变速率和温度对Ｔｉ４５Ａｌ１０Ｎｂ合金的屈服强度和延伸率的影响。结果表明：随着应经升高,合金的屈服强度升高而延伸率下降,由此得到韧脆温度ＴＢＤＴ随应变束率升高而升工计算出Ｔｉ４５Ａｌ１０Ｎｂ合金韧脆转变的激活能为３３０ＫＪ／ｍｏｌ。这一数值与ｒ－ＴｉＡｌ合金中原子的自扩散激活能（２９０ＫＪ／ｍｏｌ）相当,说明Ｔｉ４５Ａｌ１０Ｎｂ合金韧脆转变过程受扩散控制的形迹机制,即位错攀移控制,ＴＥＭ形     

氢化Ti—25Al—10Nb—3V—1Mo铸态合金的热压缩行为及其显微组织

利用等温热压缩方法在９００－１０００℃范围内，研究了氢化对Ｔｉ３Ａｌ基的Ｔｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１Ｍｏ合金热变形行为的影响，并分析了显微组织的变化。氢为０．２％的试样可使峰值流变应力比未氢化试样降低３７％－４５％，即相当于降低热压缩温度约５０℃，氢化促进合金的α２相动态再结晶，球化及β相的动态回复。     

冷轧纯钛晶界脆化和应力腐蚀

探讨了通过等温锻造及热处理改善Ｔｉ－４５Ａｌ－１０Ｎｂ－０．１Ｙ显微组织，提高其室温塑性的途径。论述了合金力学性能与显微组织的关系。     

氯化法生产四氯化钛中泥浆的回收处理

用机械合金化工艺制备了Ａｌ－１２Ｔｉ－６Ｎｂ合金，对其物相组成和显微组织进行了ＸＲＤ、电子探针和金相分析与观察，测试了其室温力学性能，并用ＳＥＭ观察了断口形貌，结果表明：ＭＡ Ａｌ－１２Ｔｉ－６Ｎｂ合金中生成了粗细不均的Ａｌ３Ｔｉ金属间化合物粒子，但未形成Ａｌ３Ｎｂ；在较大的Ａｌ３Ｔｉ颗粒和Ｎｂ趋向于平行热压面分布。Ｎｂ的加入使合金较好地发挥了大个Ａｌ３Ｔｉ和盘状Ｎｂ颗粒的协同补强增韧作用，三点弯     

微量硼和应变速率对变形TiAl合金室温力学性能的影响

以形变Ｔｉ４７Ａｌ２Ｍｎ２Ｎｂ合金为对象,研究了微量硼合金化和应变速率对ＴｉＡｌ合金室温力学性能的影响。发现添加微量（１．０％,摩尔分数）硼就能有效地细化形变Ｔｉ４７Ａｌ２Ｍｎ２Ｎｂ合金的近全片层组织,显著提高其室温强度,并在一定程度上改善室温塑性;变形ＴｉＡｌ合金不论添硼与否,其室温强度均随应变速率的升高而升高,而延伸率对应变速率不太敏感;微量硼合金化和应变速率对变形ＴｉＡｌ合金室温断裂方式无明显影响。     

METASTABLE STATE TRANSFOR MATIONS OF Al_3Ti BASE ALLOYS DURING MECHANICAL MILLING AND SUBSEQUENT ANNEALING

１　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｃｏｎｓｉｄｅｒｅｄｔｈａｔｔｈｅｂｒｉｔｔｌｅＡｌ３ＴｉｉｎｔｅｒｍｅｔａｌｌｉｃｃｏｍｐｏｕｎｄｃａｎｂｅｄｕｃｔｉｌｉｚｅｄｂｙｃｈａｎｇｉｎｇｉｔｓｔｅｔｒａｇｏｎａｌＤＯ２２ｓｔｒｕｃｔｕｒｅｉｎｔｏｔｈｅｃｕｂｉｃＬ１２ｓｔｒｕｃｔｕｒｅａｎｄｃｏｎｓｉｄｅｒａｂｌｅｓｔｕｄｉｅｓｈａｖｅｂｅｅｎｃｏｎｄｕｃｔｅｄｔｏｄｅｖｅｌｏｐｔｈｅＬ１２Ａｌ３ＴｉａｌｌｏｙｓｂｙａｌｌｏｙｉｎｇｗｉｔｈＦｅ,Ｍｎ,Ｃｒ,ｅｔｃ．Ｈｏｗｅｖｅｒ,ｔｈｅｒ…     

Effect of Yttrium on Microstructure and Properties of High Temperature Alloys

ＩｎｔｒｏｄｕｃｔｉｏｎＩＭＩ８２９ｔｉｔａｎｉｕｍａｌｏｙｉｓａｋｉｎｄｏｆｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｎｅａｒαａｌｏｙ．Ｉｔｓｓｅｒｖｉｃｅｔｅｍｐｅｒａｔｕｒｅｉｓｕｐｔｏ５８０℃．ＩｔｈａｓｂｅｅｎｕｓｅｄｉｎＲＢ２１１５２５Ｅ４ｅｎ...     

Oxidation and tribological properties of anodized Ti45Al8.5Nb alloy

The oxidation performance and tribological properties of the anodized Ti45Al8.5Nb were investigated. Anodization was performed in ethylene glycol containing 0.15 mol/L NH₄F. Results showed that the anodized Ti45Al8.5Nb alloy exhibited good resistance against oxidation. After 100 h oxidation at 1000 °C, the mass gain of the anodized Ti45Al8.5Nb alloy was only 0.37 mg/cm². This is attributed to the generation of protective oxide scale. On the other hand, the hardness and elastic modulus of the anodized Ti45Al8.5Nb alloy decreased and then increased with the prolonging of thermal exposure due to the generation of the Al₂O₃-enriched outermost oxide layer.     

Microstructure and mechanical properties of Ti 45Al 5Nb + (0–0.5C) sheets

The possible application of gamma titanium aluminides in aerospace industry requires a detailed understanding of the microstructure–property relationship of sheets made from this material. This paper reports the mechanical properties of sheets up to 1000 °C, based on alloy concepts with high Nb concentrations and small additions of C. Sheets were manufactured by rolling powder metallurgical compacts with compositions Ti 45Al 5Nb and Ti 45Al 5Nb 0.5C. The microstructures of both sheets are “near gamma” and consist of γ-TiAl and ₂-Ti₃Al phases. The texture of both phases is very weak. The strengths levels are very high and that of the C-containing sheet exceeds that of the C-free material at RT by 200 MPa. The mechanical properties of Ti 45Al 5Nb are independent of the direction in the sheet, in the whole temperature range from RT to 1000 °C. However, for the C-containing sheet this is true only in the upper temperature range.     

Nb对TiNiAl合金高温氧化行为的影响

对Ti50Ni44Al6和Ti50Ni41Al6Nb3合金在1073K循环氧化行为的测试表明，Nb的加入显著改善合金的高温抗氧化性能．Ti50Ni44Al6合金在1073K经过100h循环氧化后形成外层以TiO2为主并含有少量Al2NiO4、内层为TiNiO3的氧化层，合金的氧化动力学服从线性规律；Ti50Ni41Al6Nb3合金生成以TiO2为主的氧化膜，在外氧化层下面形成了一层富Nb和Al的复合氧化物，显著阻碍氧以及合金元素的扩散，降低了合金的氧化速率，合金高温氧化动力学遵从抛物线规律．     

High speed ball nose end milling of γ-TiAl alloys

Following a brief review on the development and intended application of γ-TiAl for aeroengine components, the paper details statistically designed machinability experiments involving high speed ball end milling in order to benchmark 4th generation alloy Ti–45Al–8Nb–0.2C against Ti–45Al–2Mn–2Nb +0.8%vol. TiB_2, which has been the prime focus of machinability evaluation and associated publications. Testing utilised 8 mm diameter, solid WC, AlTiN coated ball nose end cutters in a factorial design and involved measurement of cutting temperatures and workpiece surface roughness in addition to tool life and cutting forces. The trials established alloy Ti–45Al–8Nb–0.2C as providing a ∼25% increase in tool life based on a maximum flank wear criteria of 300 μm. On average, alloy Ti–45Al–2Mn–2Nb +0.8%vol. TiB₂ had a surface roughness Ra of ∼0.1 μm higher than Ti–45Al–8Nb–0.2C with values <0.6 μm Ra possible. Maximum cutting temperatures for Ti–45A–8Nb–0.2C measured using infra red pyrometry were ∼250 °C at a cutting speed of 160 m/min for a new tool, rising to ∼430 °C at a cutting speed of 340 m/min with a tool that had 300 μm of flank wear. For both γ-TiAl alloys, fracture/pullout was observed on every milled surface that was assessed and varied from a few microns to a few millimeters depending on test operating levels, within general, higher cutting speeds and tool flank wear levels causing an increased level of damage.     

AP-FIM STUDY ON THE MICROSTRUCTURES OF TiAl INTERMETALLIC COMPOUNDS FXBRICATED BY INGOT METALLURGY AND CENTRIFUGAL SPRAY DEPOSITION

1. IntroductionTitanium aluminide alloys based on the ac-TiAl phase are attractive materials for hightemperature structural application. The strength and ductility of two-phase TiAl alloys aremainly decided on microstructural size and morphologiesll32]. The mechanical propertiesof ac--TiAl alloys can be widely changed by microstructural control with millor alloyingand processing. It will be seen that an advanced processing, centrifugal spray deposition(CSD), can offer alloys with a refined…     

不同SPS烧结温度Ti-45Al-5.5(Cr,Nb,B,Ta)合金的显微组织及力学性能(英文)

采用高能球磨和放电等离子烧结(SPS)技术,制备成分为Ti-45Al-5.5(Cr,Nb,B,Ta)的TiAl合金块体,随后对TiAl合金进行热处理。研究在不同SPS烧结温度下制备的TiAl合金经过热处理后的显微组织和力学性能。结果表明:高能球磨后的合金粉末形状不规则,粉末颗粒尺寸大约为几十微米。XRD分析表明,机械球磨后的粉末由TiAl和Ti3Al两相组成;烧结后的Ti-45Al-5.5(Cr,Nb,B,Ta)合金块体主要是TiAl相,以及少量的Ti3Al和TiB2相。当烧结温度为900°C和1000°C时,合金的显微组织为双相结构,并伴随有一些细小的等轴γ晶粒和细小的针状TiB2相。当烧结温度从900°C上升到1000°C时,Ti-45Al-5.5(Cr,Nb,B,Ta)合金的显微硬度变化不大,抗压强度从1812MPa提高到2275MPa,压缩率从22.66%增加到25.59%,合金的断裂方式为穿晶断裂。