Ti-1300F高强钛合金丝材热处理工艺优化

采用正交试验方法,研究了固溶温度、时效温度和时效时间对?6.5 mm Ti-1300F合金丝材室温拉伸性能和显微组织的影响。结果表明:经α+β两相区固溶+时效处理后,合金的显微组织由细小等轴初生α相、弥散针状次生α相和β基体组成。时效温度对合金强度和塑性的影响最为显著,固溶温度次之,时效时间的影响最小。根据试验结果对热处理工艺进行了优化,经(760～790)℃/1 h, WQ+(500～540)℃/4 h, AC处理后,Ti-1300F合金丝材获得强度和塑性的良好匹配。     

固溶温度对TB10钛合金力学性能的影响

研究了固溶温度对TB10(Ti-5Mo-5V-2Cr-3Al)钛合金在热处理过程中力学性能变化规律。结果表明:当TB10钛合金在740～840℃之间固溶,并在520℃时效时,在相变点以下固溶,随着固溶温度的升高,材料的强度降低、塑性升高,但在800℃时网状晶界α相恶化了材料的塑性,在相变点以上固溶时,材料的强度和塑性随着固溶温度的升高而下降;时效后的TB10钛合金随着固溶温度升高,材料的强度升高、塑性下降;当固溶温度为740℃时,时效态的材料强度和塑性比固溶态略有升高,固溶温度越高,时效强化效果越显著,时效态材料的塑性比固溶态的低,但在800℃时由于晶界α相的网状被破坏使时效态材料的塑性比固溶态的高。     

固溶时效对Ti-6Cr-5V-5Mo-4Al-1Nb合金组织和力学性能的影响

研究了固溶温度、时效温度、时效时间对Ti-6Cr-5V-5Mo-4Al-1Nb(Ti-65541)合金显微组织与力学性能的影响。结果表明,在β相变点以上固溶并时效后,合金中析出细小的次生α相,初生α相完全消失;在较低温度固溶并时效后,次生α相和初生α相同时存在。时效温度对合金强度和塑性的影响最为显著,固溶温度次之,时效时间的影响最弱。随着时效温度的升高,合金的抗拉强度和屈服强度降低,塑性提高。随着固溶温度的提高,合金的强度提高,塑性降低。随着时效时间的延长,合金强度和塑性总体呈降低趋势。在740～760℃范围内固溶处理,在540～580℃范围内时效且时效时间在4～6 h内,可获得综合性能优异的Ti-65541合金。     

热处理对TC21合金大规格棒材组织和性能的影响

研究了不同热处理制度对TC21合金380 mm大规格棒材显微组织和力学性能的影响。结果表明,固溶温度影响初生α相含量以及形貌尺寸,固溶时间对显微组织没有显著的影响;冷却速度影响次生α相含量及尺寸,且对合金强度和塑性产生较大的影响。在890℃×2 h+FC固溶处理后进行610℃×4 h+AC时效处理,可使合金的强度和塑性得到良好的匹配。     

不同热处理工艺下TC4-DT钛合金的显微组织及力学性能

研究了几种热处理制度对TC4-DT钛合金板材显微组织和力学性能的影响。结果表明:等轴或双态组织具有好的拉伸性能,片层组织能够有效提高材料的断裂韧性;控制单相区固溶的冷却速度以及第二重热处理的温度和冷却速度,可以获得不同尺寸的片层组织;单相区固溶后空冷,再经两相区第二重热处理,空冷的组织中含有粗的初生α片层和细小的次生α片层,炉冷的组织中α片层变厚,单相区固溶后水冷得到马氏体组织,在两相区热处理保温时,马氏体组织直接分解成粗的α片层。采用1 015℃/1 h/AC+955℃/1.5 h/AC+550℃/6 h/AC多重热处理,可以获得粗细相间的片层组织,具有更好的强度-塑性-断裂韧性的综合匹配。     

热处理对热加工态TB2钛合金显微组织及力学性能的影响

研究了常规固溶+时效、双时效及固溶+预时效+时效处理对热加工态TB2钛合金显微组织及力学性能的影响。显微组织研究表明:通过增加低温预时效工艺,可以使经热处理后的TB2钛合金中析出的次生α相较经常规固溶+时效处理后的更加均匀、细小。力学性能分析表明:经常规固溶+时效处理后,TB2钛合金的塑性较好,但强度偏低;双时效处理可以提高TB2钛合金的强度,但塑性较差;固溶+预时效+时效处理后,TB2钛合金的强度与塑性匹配良好。进一步热处理工艺研究表明:经780℃×1 h/AC+350℃×6 h/AC+560℃×8 h/AC热处理后,TB2钛合金的强度与塑性达到最优匹配,抗拉强度为1 190 MPa,延伸率为14%。     

热处理工艺对BT25钛合金锻件的组织与性能的影响

研究了不同固溶温度及冷却方式对BT25钛合金锻件组织与性能的影响。结果表明：同一固溶温度下,空冷的比炉冷的显微组织细小。固溶温度在相变温度以上,空冷的比炉冷的室温强度高,但塑性指标及冲击韧性变化不大。固溶温度在相变温度以下,同一固溶温度下空冷的比炉冷的室温强度稍高、断面收缩率和冲击韧性要高的多、延伸率变化不大,但屈服强度略有下降。高温强度随着冷却速度的提高而呈现略有提高趋势,塑性指标变化不明显。选用固溶温度为相变点以下30-40℃,保温2h空冷＋550℃,6h空冷热处理制度,可以保证合金强度和塑性的最佳配合。     

热处理对Ti-3Al-5Mo-4Cr-2Zr-1Fe合金组织与力学性能的影响研究

对Ti-3Al-5Mo-4Cr-2Zr-1Fe(Ti-35421)合金进行了不同工艺的固溶时效处理,研究了热处理后的组织演变规律与力学性能。结果表明：经不同温度固溶+540℃时效后,随着固溶温度的升高,初生α相板条变短变粗,体积分数减少,针状次生α相体积分数增加,Ti-35421合金的强度增加,塑韧性减小,拉伸断口表面韧窝数量减少、尺寸变小,逐渐出现微孔和空洞;经775℃固溶+不同温度时效后,随着时效温度的升高,针状次生α相变短变粗,次生α相间距增大,合金的强度减小,塑韧性增加,拉伸断口表面韧窝逐渐变大变深,微孔和空洞逐渐消失。当热处理工艺为775℃/1 h/AC+560℃/16 h/AC时,Ti-35421合金的抗拉强度为1125 MPa,屈服强度为1024 MPa,延伸率为5.5%,冲击吸收功为36.3 J,具有良好的强塑韧性匹配。     

不同热处理工艺对工业TC4合金板材组织和性能的影响

研究了两相区普通热处理和β相区固溶+两相区固溶双重热处理对工业TC4合金板材组织和性能的影响。结果表明:两相区普通退火处理(分别在700,750,800℃保温1 h,空冷)可以得到较好的综合性能,随温度升高,晶粒略有长大,强度、塑性逐渐降低;β相区固溶+两相区固溶双重热处理(1 050℃×30 min,AC+720℃×2 h,AC)得到网篮组织,强度、塑性明显降低。     

热处理对X-5钛合金棒材组织与性能的影响

研究了ф16 mm的X-5钛合金棒材在不同热处理条件下的显微组织和力学性能。结果表明:采用800℃×60min/AC和850℃×10 min/AC进行固溶处理,ф16 mm的X-5钛合金棒材可以获得较好的显微组织和室温力学性能;在800℃×60 min/AC+500℃×8 h/AC的固溶加时效制度下,ф16 mm的X-5钛合金棒材可以获得最好的强化效果,且塑性也能满足设计需要;不同的固溶冷却方式则对ф16 mm的X-5钛合金棒材的室温力学性能影响不大。     

Correlation of tensile properties, deformation modes, and

The effect of plastic deformation mode on tensile properties of quenched commercial β-phase titanium alloys has been investigated at approximately constant grain size and oxygen content. In addition, stability of β-phase has been estimated from ω-reflections or diffuse streaking in electron diffraction patterns in a manner similar to the previous works on binary β-phase titanium alloys. Dominant mode of plastic deformation is 332 〈113〉 twinning in the alloys with large instability of β-phase, such as Ti-ll.5Mo-6Zr-4.5Sn and Ti-15Mo-5Zr, and is crystallographic slip in the alloys with small instability of β-phase, such as Ti-15Mo-5Zr-3Al, Ti-3Al-8V-6Cr-4Mo-4Zr, Ti-15V-3Cr-3Al-3Sn, Ti-8Mo-8V-2Fe-3Al, and Ti-13V-11Cr-3Al. Twinning leads to low yield strength and large elongation, while slip results in high yield strength and small elongation in agreement with binary and ternary β -phase titanium alloys.     

双相区固溶温度对Ti-55531合金组织和力学性能的影响

通过对Ti-55531合金在双相区不同温度(730~830℃)固溶2 h空冷后,经相同的时效工艺(600℃/6 h/空冷(AC))处理;再结合扫描电子显微镜(SEM)和拉伸试验等分析方法,系统研究了双相区不同固溶温度对该合金组织和力学性能的影响规律。结果表明,随固溶温度的升高,等轴αp含量降低,尺寸减小;后续时效析出的αs含量增多,形态也有显著变化,由全短棒状向短棒状+针状、针状+长片状、全长片状的顺序转变。固溶温度从730℃升高到780℃,塑性较好的αp含量减少导致合金塑性降低,αs含量增加导致合金强度提高;固溶温度从780℃升高到800℃,αs含量继续增多导致合金强度上升,适量的长片状αs促进了合金塑性提高;固溶温度从800℃升高到相变点830℃,过多的长片状αs导致合金强度和塑性都显著下降。合金的强塑性匹配较好时对应的固溶温度为780~800℃。合金的断裂方式都是以微孔聚集型为主、含解理撕裂和沿晶开裂的混合断裂机制,且随固溶温度的增加,合金塑性断裂机制减小,脆性断裂机制增加。     

Fabrication and properties of heavy section extrusions of Ti-6Al-6V-2Sn and Ti-8Mo-8V-2Fe-3AI alloys

This study is concerned with the fabrication in heavy section of the titanium alloys Ti-8Mo-8V-2Fe-3Al (Ti-8823) and Ti-6Al-6V-2Sn (Ti-662). The technique utilized to achieve 84 pct reduction during the extrusion of heavy section cylindrical hollows is given. The response to subsequent aging of both alloys is described in terms of the effect on important mechanical properties such as yield and ultimate tensile strength, ductility and fracture toughness. For the Ti-8823 alloy extruded in heavy section, it is shown that the optimum heat treatment consists of aging directly after hot working rather than the more common solution treatment and age cycle. With the former heat treatment, uniform through the thickness mechanical properties are obtained. Uniform mechanical properties are also obtained through the section of the Ti-662 extrusion with a solutionizing and overaging heat treatment.     

Correlation of tensile properties,deformation modes,and phase stability in commercial β-phase titanium alloys

The effect of plastic deformation mode on tensile properties of quenched commercial β-phase titanium alloys has been investigated at approximately constant grain size and oxygen content. In addition, stability of β-phase has been estimated from ω-reflections or diffuse streaking in electron diffraction patterns in a manner similar to the previous works on binary β-phase titanium alloys. Dominant mode of plastic deformation is {332}<113> twinning in the alloys with large instability of β-phase, such as Ti-11.5Mo-6Zr-4. 5Sn and Ti-15Mo-5Zr, and is crystallographic slip in the alloys with small instability of β-phase, such as Ti-15Mo-5Zr-3Al, Ti-3Al-8V-6Cr-4Mo-4Zr, Ti-15V-3Cr-3Al-3Sn, Ti-8Mo-8V-2Fe-3Al, and Ti-13V-11C-3Al. Twinning leads to low yield strength and large elongation, while slip results in high yield strength and small elongation in agreement with binary and termary β-phase titanium alloys.     

固溶温度对Ti-62A合金拉伸性能和断裂韧性的影响

Ti-62A合金是一种新型高强高韧损伤容限型钛合金,研究了固溶温度对Ti-62A合金30 mm厚板材的显微组织、拉伸性能以及断裂韧性的影响规律。研究结果表明:Ti-62A合金Φ720 mm铸锭经单相区和两相区多道次大变形轧制后所得的30 mm厚板材组织为典型的片层组织,由片层状的α相和β转变组织构成,组织均匀,片层状α相平均宽度约为2.5μm,长度在40～65μm之间。两相区固溶+时效处理后,合金的组织类型为片层状组织,即片层状的初生α相(αp)相与β转变组织,随固溶温度升高,合金中的初生α相(αp)相含量显著减少,β转变组织逐渐增多,次生α相(αs)片层宽度增大,同时合金的强度下降,塑性上升,当接近相变点时这种趋势变缓。单相区固溶+时效处理获得魏氏组织,晶粒粗大,晶界平直而清晰,其拉伸强度高于920℃和940℃固溶时的片层组织,但塑性显著降低;与900℃固溶时相比强度和塑性均降低。合金的断裂韧性随固溶温度的上升而逐渐升高,单相区固溶并时效后的魏氏组织的断裂韧性明显优于两相区固溶并时效后的片层组织。     

The influence of microstructure on mechanical properties in Ti-3AI-8V-6Cr-4Mo-4Zr (Beta-C)

The effect of microstructure on mechanical properties of a metastable beta titanium alloy has been investigated, with emphasis on the influence of α-phase precipitation on tensile strength and ductility. A commercial alloy, Ti-3Al-8V-6Cr-4Mo-4Zr (Beta-C) has been aged to produce both Type la (obeying the Burgers orientation relation) and Type 2α (not obeying the Burgers relation) as hardening precipitates in the beta matrix. Although a direct comparison of Types 1 and 2α could not be made, there did not seem to be any direct correlation between precipitate type and mechanical properties. Rather, it has been found that overaging to produce a coarse distribution of relatively large (>1000Å) noncoherent α precipitates provides the best combination of strength and duc-tility. The same strength can be achieved with a much finer distribution of small (～100-200A) coherent α precipitates, but with much reduced ductility.     

热处理制度对Ti-55531合金组织和力学性能的影响

通过采用不同的热处理制度研究了时效温度和β退火温度对Ti-55531合金显微组织和力学性能的影响。结果表明:Ti-55531合金固溶加时效处理后可获得初生α相呈长条或等轴状的组织,β基体上大量析出的次生α相使其获得较高的强度,且强度随时效温度升高而显著降低,延伸率变化不明显,断面收缩率在620℃以上随着时效温度升高有所增加,但该组织状态断裂韧度偏低;β退火后可获得均匀的片状组织,具有较高的断裂韧性,抗拉强度在600~650℃之间随退火温度升高呈线性关系降低,可根据需要很方便地调整强度级别,塑性随退火温度升高变化不太明显。     

Direct Laser Fabrication of Ti-25V-15Cr-2Al-0.2C (wt?pct) Burn-Resistant Titanium Alloy

Direct laser fabrication has been used to deposit multilayers of burn-resistant titanium alloy onto the surface of Ti697 (Ti-11Sn-5Zr-2.25Al-0.25Si) alloy by feeding Ti-25V-15Cr-2Al-0.2C (wt pct) powder into the laser molten pool. The microstructure and mechanical properties of the deposited layers have been studied to identify the importance of laser conditions on properties/microstructure. The observations are discussed in terms of the optimum laser conditions and thus the potential of using BuRTi (Ti-25V-15Cr-2Al-0.2C) to tip blades of high-temperature titanium alloys to provide burn resistance.     

热处理对TC18钛合金丝显微组织与力学性能的影响

研究了热处理对TC18钛合金丝材显微组织与力学性能的影响。研究结果表明,对于多道次热拉2.0 mm丝材,随着退火温度由760℃升高至820℃,显微组织明显发生了再结晶和晶粒长大过程,并且α相含量显著减少,β相含量显著增多。随着温度的升高,抗拉强度呈明显下降趋势,由760℃时的1 110 MPa下降到820℃时的970MPa。在760℃退火时,保温时间由0.5 h延长到1.5 h,丝材的显微组织晶粒略有长大,力学性能略有降低。