飞机结构用TC11钛合金异型锻件的组织与性能

介绍了在工业化条件下,通过合理的工艺路线锻制TC11合金异型锻件.并进行了不同热处理制度下异型锻件的组织和性能试验研究.结果表明：采用950℃,2 h空冷＋530℃,8 h空冷热处理后的锻件的显微组织为均匀的α＋β组织,且有较好的综合室温力学性能,其室温性能为：σb：1050MPa～1100MPa,σ0.2：950MPa～1020MPa,δ5：15%～18%,ψ：32%～36%,αku：45.7 J/cm^2～51.7 J/cm^2,其它各项技术性能也符合协议标准要求,满足航空部门需求.     

新型奥氏体不锈钢室温拉伸性能研究

研究了新型奥氏体不锈钢24Mn18Cr3Ni0.62N在室温下的拉伸性能。结果表明,该钢具有优良的室温拉伸性能,σ0.2=525MPa,σb=890MPa,δ=41%,ψ=57%,n=0.421。室温下断裂为韧性断裂,夹杂物为裂纹发源地之一,净化材料可以进一步提高材料的抗拉强度。     

新型压力容器用钢的热处理与性能

研究了新型压力容器用钢的热处理与性能。结果表明,该钢经960℃×1.5h水淬+630℃×1.5h空冷回火后,可获得最佳性能:σ0.2=640MPa,σb=740MPa,δ=21%,ψ=75%,AKV=323J,硬度203HB。室温组织为铁素体及弥散的析出物。     

低碳微合金容器钢经调质处理后的组织与性能

本文研究了含碳0.09%的低碳微合金容器钢的组织与性能。结果表明该钢经调质处理(960℃×1.5 h+630℃×1.5 h)后,获得的性能为:0σ.2=641 MPa,σb=742 MPa,δ=20%,ψ=75%,AKV=321 J,HB=204。室温组织为铁素体及弥散的析出物。     

NiCrAlYSi涂层对IC10合金力学性能的影响

采用电弧离子镀技术在IC10合金基体上制备出厚度为30μm的NiCrAlYSi涂层,研究NiCrAlYSi涂层对IC10合金拉伸、持久、疲劳性能的影响.结果表明,IC10合金沉积NiCrAlYSi涂层后,在980℃,200MPa高温持久寿命与IC10合金相当,在900℃的高温抗拉伸强度σb、屈服强度σ0.2、延伸率δ和面缩率ψ与基体相比,基本保持不变:室温抗拉伸强度σb.屈服强度σ0.2与基体相比稍有下降,在800℃,447MPa疲劳寿命与基体合金相当,即IC10合金沉积NiCrAlYSi涂层后,对IC10合金力学性能基本没有影响,满足使用要求.     

新型奥氏体不锈钢室温拉伸性能研究

研究了新型奥氏体不锈钢24Mn18Cr3Ni0．62N在室温下的拉伸性能。结果表明．该钢具有优良的室温拉伸性能，σ0.2=525MPa，σb=890MPa，δ=41％，ψ=57％，n=0.421。室温下断裂为韧性断裂，夹杂物为裂纹发源地之一，净化材料可以进一步提高材料的抗拉强度。     

Si增强快速凝固/粉末冶金AZ91镁合金的制备

采用自制的雾化-激冷设备,用快速凝固粉末冶金方法制备了Si增强AZ91镁基复合材料,分别对材料进行光学金相、XRD、显微硬度、拉伸性能以及SEM分析。结果表明:增强相在基体中分布均匀,在挤压过程中增强相与基体发生了反应,形成反应层,反应层中存在高温相Mg2Si。复合材料的室温δ、σb、σ0.2分别为3.50%、322.35 MPa和241.60 MPa。随着Si含量的提高,该复合材料的性能明显下降。该复合材料表现出较好的高温性能,423 K时,其δ、σb、σ0.2分别为5.2%、302 MPa和227 MPa。     

BT8钛合金轧棒的组织与性能

研究了宝鸡钛业股份有限公司生产的BT8钛合金在不同轧制工艺下棒材的组织与性能。不同显微组织的BT8轧棒的室温性能为：Rm31075MPa，Rr0．2≥983MPa，A≥13％-17％，Z≥22％-45％；500℃拉伸性能：σb≥748MPa～768MPa，σ0．2≥595MPa-610MPa，δ≥19％～23％，ψ≥365％。71％。研究表明该合金具有电好的综合性能。     

热机械处理对Ti-45Al-5Nb-0.3Y合金的显微组织与力学性能的影响

包套锻造Ti-45Al-5Nb-0.3Y合金由大量细小的动态再结晶等轴γ晶粒(晶粒尺寸可达1-2 μm),弯曲或破碎的层片和少量的残余平直层片组成,变形组织含有人量位错及少量变形孪晶.锻态试样抗拉强度(σb),延伸率(δ)分别达到708.1 MPa和0.95%.再通过不同的热处理分别得到晶粒细小的双态组织、近层片组织和全层片组织.经1320 ℃/30 min炉冷后得到双态组织,层片晶粒尺寸(d1)约为20 μm,层片体积分数(ψ1)约为60%,具有最高的δ,约为1-9%,σb约为658.9 MPa,为穿晶和沿晶混合断裂;经1340℃/30 min炉冷后得到近层片组织,dI约为60 gm,ψ1约为95%,O'b约为690.2 MPa,δ约为1.75%,上要为穿晶(层片)断裂;经1370℃/15 min炉冷后得到细小全层片组织(d1约为40 μm),具有最高的σb,约为715.1 MPa,5约为1.51%,为穿晶断裂.     

高低温处理条件下AZ31镁合金的力学性能与微观组织

针对月球环境温度变化情形,研究了长时间低温浸泡(-196℃)和多次高低温交变循环处理(-196～200℃)对挤压态AZ31镁合金在20℃下的力学性能、显微组织以及断口形貌的影响.研究表明:AZ31镁合金经过长时间液氮浸泡和高低温交变循环处理后,力学性能无明显变化;室温态合金的σb和δ分别为288 MPa和18.3％,经过10 d低温浸泡后σb和δ分别为292 MPa和18.7％,经过10次高低温循环后合金的σb和δ分别为294 MPa和16.9％;低温和高低温交变处理对断口形貌和相组成没有明显影响,均为准解理断裂.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。