Cu-1.5Ni-0.27Si合金形变热处理

利用力学性能、电学性能测试，金相、电镜观察及电子衍射分析研究了不同形变热处理条件下Cu-1．5Ni-0．27Si合金性能与显微组织的关系。结果表明：该合金经850℃快速热轧淬火后表现为明显的变形组织，无动态再结晶现象，只有极少量的第二相析出。450℃时效4h处理后，其显微硬度达到峰值(HVl58)，相对电导率达44％(IACS)。δ-Ni2Si析出相粒子的平均尺寸约为15nm，间距约为10～30nm，与铜基体存在确定的位向关系：(110)m//(211)ppt，[1l0]m∥[324]ppt。合金经80％的冷轧变形后，σb、σ0.2、显微硬度、延伸率和相对电导率(IACS)分别达578MPa、573MPa、HV173、3％和41．5％。合金的强化机制为Orowan位错绕过机制。     

Structure and mechanical properties of alloys Ti-2.2% Al-2.2% V-2.2% Mo-2.5% Fe and Ti-2.2% Al-5% Fe equivalent to alloy VT16

Comparative studies of the structure and properties of alloys Ti-2.2% Al-5% Fe and Ti-2.2% Al-2.2% V-2.2% Mo-2.5% Fe in annealed, quenched, and aged conditions are performed. The strength level of the alloys corresponds to that of VT16. The possibility of replacing alloy VT16 by alloy Ti-2.2% Al-2.2% V-2.2% Mo-2.5% Fe is estimated. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 10–13, June, 2006.     

热处理工艺对Cu-16．2AI-9．9Mn合金形状记忆效应的影响

通过弯曲测试法、电阻法和显微组织分析等方法研究了淬火后时效处理温度和分级淬火温度对Cu-16-2Al-9.9Mn(at%)合金相变温度、微观组织及形状记忆效应的影响.结果表明,Cu-16.2Al-9.9Mn合金淬火后的形状记忆效应偏低.采用淬火后时效和分级淬火处理后,合金的形状记忆效应由于热弹性马氏体的出现得到较大提高.合金的形状记忆效应和相变温度随着时效温度和分级淬火温度的升高逐步提高,分级淬火处理后的形状记忆效应低于相同温度时效后的形状记忆效应.     

Using differential scanning calorimetry to characterize the precipitation hardening phenomena in a Cu-9Ni-6Sn alloy

An attempt has been made to characterize the transformations in a Cu-9Ni-6Sn alloy using heat flux differential scanning calorimetry (DSC) assisted by hardness measurements. Both solution heat treatment and precipitation transformations have been studied. Different starting conditions were imposed on the material to allow a clearer understanding of the transformations involved. The precipitation from the supersaturated solid solution happens in two temperature ranges, i.e., from 200 to 400 °C and from 440 to 600 °C. In the temperature range from 400 to 440 °C, the alloy does not usually transform. Thermal cycles leading to aging and overaging were determined. The precipitation hardening conditions at 350 °C or lower for less than 600 min, or 375 °C for up to 120 min, lead to metastable precipitation. Precipitation hardening for 120 min at 400 °C or 1200 min at 350 °C results in stable precipitation and is responsible for overaging the alloy.     

热处理对激光立体成形新型Ti-6Al-6Mo合金显微组织和硬度的影响

以混合元素粉末为原料,采用激光立体成形(Laser solid forming, LSF)技术制备新型Ti-6Al-6Mo合金。研究了沉积态试样的显微组织以及固溶时效处理对合金显微组织形成及硬度的影响。结果表明,本研究所采用的热处理制度对原始β晶粒形貌没有显著的影响;固溶温度、固溶时间和固溶后的冷却方式对原始β晶粒中α相的形貌和尺寸以及LSF Ti-6Al-6Mo合金的显微硬度均有显著影响。当时效时间超过4小时后,随着时效时间的延长,合金的显微组织和显微硬度均未产生明显变化。基于不同热处理条件下LSF Ti-6Al-6Mo合金中初生α板条和次生α板条的析出机制及其对β基体的强化作用分析,揭示了热处理对LSF Ti-6Al-6Mo合金的显微组织和显微硬度的影响机理。     

热处理对粉末冶金Cu-15Ni-8Sn合金组织与性能的影响

以Cu-15Ni-8Sn合金粉为原料制备了粉末冶金试样,研究其在不同的固溶温度、冷压变形、时效温度和时效时间条件下的硬度,着重研究了840℃×15 min固溶+40%冷压变形条件下时效温度和时间对硬度及剪切强度的影响规律,采用金相及扫描电镜分析了相应的微观组织。结果表明,影响Cu-15Ni-8Sn合金硬度的主次因素为:冷压变形量>时效时间>时效温度>固溶温度,较优的工艺参数为840℃×15 min固溶+40%冷压变形+400℃×4 h时效,可获得37.6～38.3 HRC的高硬度和570～628 MPa的抗剪切强度。     

超高强度Cu-5.2Ni-1.2Si合金的形变热处理

研究不同形变热处理条件下Cu-5.2Ni-1.2Si合金的性能与显微组织结构,对合金的力学性能和电学性能进行测量,并采用金相显微镜、透射电镜及电子衍射分析其显微组织。结果表明：时效前的冷变形可以加速时效析出过程,在时效初期尤为明显;在450℃时效时该合金的峰时效有3种强化机制：调幅组织强化、析出的第二相粒子强化和有序强化;析出的第二相粒子主要是Ni2Si粒子;采用铸锭—热轧—冷轧（变形量为60%）—时效工艺处理的合金可以得到硬度和导电率的最优组合。     

Thermomechanical treatment of super high strength Cu-8.0Ni-1.8Si alloy

The microstructures and properties of Cu-8.0Ni-1.8Si alloy subjected to different heat treatments were examined by mechanical and electrical properties measurements, optical and transmission electron microscopes observation. The results show that the precipitation process during aging can be accelerated by the cold deforming before aging. As the Cu-8.0Ni-1.8Si alloy is subjected to solution treatment at 970 ℃ for 4 h, cold rolling to 60% reduction, and then aging at 450 ℃ for 60 min, its properties are σb=1 050 MPa, σ0.2=786 MPa, δ=3.2% and conductivity 27.9%（IACS）. The strengthening mechanisms of the alloy include spinodal decomposition strengthening, ordering strengthening and precipitation strengthening. The precipitation of the alloy is nano-scale Ni2Si phase.     

喷射沉积Al-17Si-5Fe-2Mn-2Ni-3.5Cu-1Mg-1V合金的组织及性能

采用喷射沉积快速凝固技术制备了Al-17Si-5Fe-2Mn-2Ni-3.5Cu-1Mg-1V合金,利用金相、X射线衍射和SEM等测试方法分析了合金的组织特征、热稳定性及力学性能。结果表明：喷射沉积合金的组织由大量弥散分布的粒状相、少量块状相和共晶基体组成。挤压态合金经300℃不同时间加热后,初晶Si相没有明显的粗化,热稳定性良好;合金经热挤压后,室温极限拉强度达232.2 MPa,经T6热处理后极限抗拉强度提高了17%,达271.3 MPa。     

Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC) cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si particle, eutectic Si, Al7Cu4Ni, Al5Cu2Mg8Si6, Al15(Cr, Fe, Ni, Cu)4Si2 and Al2Cu. The Al2Cu phase dissolves completely after being solution treated for 2 h at 500℃, while the eutectic Si, Al5Cu2Mg8Si6 and Al15(Cr, Fe, Ni, Cu)4Si2 phases are insoluble. In addition, the Al7Cu4Ni phase is substituted by the Al3CuNi phase. The α-aluminum dendrite network disappears when the solution temperature is increased to 530℃. Incipient melting of the Al2Cu-rich eutectic mixture occurrs at 520℃, and melting of the Al5Cu2Mg8Si6 and Al3CuNi phases is observed at a solution temperature of 530℃. The void formation of the structure and deterioration of the mechanical properties are found in samples solution treated at 530℃.     

通过双级固溶热处理制备新型高强Al−10.5Si−3.4Cu−0.2Mg合金

通过析出硬化提高Al?Si?Cu合金的力学性能.这些合金对时效硬化的反应非常缓慢.为了解决这一问题,在Al?10.5Si?3.4Cu合金中分别加入0.2％、0.4％和0.7％(质量分数)的镁.该新型合金在固溶处理阶段经过两种不同的析出硬化过程.结果表明,添加不同含量的镁可加速该合金对时效处理的响应,提高其硬度和强度.双...     

Cu—0.35Zr合金热处理后的显微组织研究

用光学显微镜(OM)、X射线衍射仪(XRD)和电子探针(EPMA)研究了在大气环境下采用普通中频感应炉制备的Cu-0.35Zr合金的显微组织.结果表明,铸态合金中的Zr以Cu3Zr形式存在;固溶时效处理后合金中的Zr元素以Cu5Zr及Cu51Zr14等形式析出,并弥散分布于铜基体上.     

热扩散处理对Al-24%Si合金中初晶硅形态的影响

采用低于Al-Si合金共晶点温度(577℃)加热保温处理,研究过共晶Al-24%Si合金在不同的加热扩散温度和保温时间下初晶硅形态的演变.结果表明:加热扩散温度为550℃,保温时间分别为3、6、9和12 h时,随保温时间的延长,粗大块状或花瓣星状的初晶硅趋于向近球状转变,且尺寸随保温时间的延长而变得细小;当保温时间为9 h,加热扩散温度为450、510、530和550℃时,随加热扩散温度的升高,初晶硅的尺寸越细小,圆整度提高,通过选择合适的加热扩散温度和保温时间进行处理可以起到使初晶硅球化和细化的效果,从而提高合金的力学性能.     

Al-7.0Zn-1.9Mg-1.1Cu-0.12Zr合金T74热处理工艺研究

通过力学性能和电导率测试,TEM和SEM组织分析,研究了Al-7.0Zn-1.9Mg-1.1Cu-0.12Zr合金板材的T74工艺及其在T74状态下的微观组织和性能。结果表明,该合金适宜的固溶热处理工艺为450℃60 min+475℃90min。选用160℃～170℃作为第二级时效温度,保温6 h～12 h可以使合金获得比较理想的T74状态组织和性能。合金在T74状态下晶界析出相粗大呈离散分布,出现明显宽化的晶间无析出带,基体中的主要析出相是η'相、η相和GPII区;合金板材的极限抗拉强度、屈服强度、伸长率和电导率分别达到490 N/mm2～515 N/mm2,455 N/mm2～475 N/mm2,13.1%～17.6%和22.9 MS/m～23.7 MS/m,L-T向断裂韧性KIC可以达到39 MPa.槡m～42 MPa.槡m。合金T74状态拉伸断口的断裂方式以韧窝断裂为主,断口上尺寸较大的第二相粒子为AlCuFe相。     

氮气雾化Al-20Si-7.5Ni-3Cu-1Mg-0.25Fe合金粉末形貌及组织

采用氮气雾化制备Al-20Si-7.5Ni-3Cu-1Mg-0.25Fe合金粉末,利用激光粒度分析仪、金相显微镜、扫描电子显微镜、X射线衍射仪和热分析仪对合金粉末的粒度分布、组织、形貌、组成相和相演变规律进行研究。结果显示,该氮气雾化粉末的中粒径为29.5μm,形貌多为球形或类球形,在尺寸较大的粉末颗粒表面存在凹坑和卫星球现象,尺寸较小的粉末表面则相对光滑。粉末内部存在块状初晶硅和片状亚稳金属间化合物,这种亚稳金属间化合物在310℃时会分解为稳定的耐热相。     

Formation of metastable phases in a Ni-9.6 wt % Al-6.7 wt % Fe-1 wt % Cr intermetallic alloy

Structural changes and the formation of metastable phase states in an Ni₃Al-based intermetallic alloy after short-term 5-h annealing at a temperature of 1000°C and upon subsequent multiple deformation of the crystal by compression to 38% at room temperature have been analyzed using transmission electron microscopy and neutron diffraction.     

时效工艺对Cu-12%Fe合金组织性能的影响

用熔铸法制备了Cu-12%Fe合金,研究了经1000℃固溶后不同时效工艺对合金的相组成、显微组织、硬度及电导率的影响.结果表明,550℃时效可细化合金的Fe枝晶.消除Cu基体枝晶偏析并改变晶面间距.合金硬度在时效初期时下降,随后增加并达到最大值后再次下降.在350℃和450℃时效时,电导率随时效时间增加而上升.在550℃和650℃时效时,电导率随时效时间先增加而后下降.对Cu-12%Fe合金固溶并在550℃时效4h,可以获得良好的力学和电学性能匹配.     

热处理对TC6钛合金内表层组织及硬度的影响

对TC6钛合金进行990℃保温热处理,研究保温过程中氧原子、合金元素分布变化对内表层组织及硬度的影响。结果表明,在990℃热处理后试样内表层富氧α层从边部到基体内部显微硬度呈现低-高-低的变化规律,在距边部约55μm处达到最大值449 HV1。内表层显微硬度的变化是由于氧化作用而导致内表层合金元素分布变化和氧原子的富集引起的。