强变形诱导析出相回溶对Al-Cu合金稳定性的影响

采用硬度检测、透射电镜观察、选区电子衍射等方法,研究了Al-Cu合金固溶态、含θ'相和含θ相的试样在强变形诱导析出相低温回溶后的加热退火过程中晶粒尺寸、高角晶界百分比及组织结构和硬度的变化.试验结果显示:当退火温度低于150℃时,A1-Cu合金三种状态的试样其晶粒尺寸与高角晶界的百分数基本上没有变化;加热温度至200℃以上后,晶粒尺寸、高角晶界百分比开始增加;加热至250 ℃时,固溶态试样的晶粒尺寸长大至100 μm左右,含析出相的试样品粒尺寸保持在10.0～15.0μm.在250 ℃退火50 min后,固溶态试样的硬度值一直低于含θ'、θ析出相试样的硬度值.     

热处理工艺对GH4151合金冲击性能的影响

采用冲击实验研究了不同温度固溶处理及固溶和双级时效处理对GH4151合金冲击性能的影响，采用光学显微镜、扫描电镜和透射电镜等观察了合金经不同工艺处理后的显微组织、析出相和断口形貌。结果表明：对于仅固溶处理的合金，当固溶温度低于1140℃时，其冲击韧性值的变化不大，固溶温度高于1140℃时，冲击韧性值随固溶温度的升高而增加，断裂过程以裂纹的稳定扩展区为主，断口呈韧性断裂。对于固溶时效处理的合金，当固溶温度低于1160℃时，冲击韧性值的变化也比较稳定，固溶温度高于1160℃时，冲击韧性值随固溶温度的升高而降低，断裂过程不存在裂纹的稳定扩展区，断口呈典型的沿晶脆性断裂。这主要是因为当固溶温度低于1140℃时，合金的晶粒尺寸变化不大，而在1140℃以上时晶粒尺寸明显增大；双级时效后，当固溶温度高于1160℃时，晶界上连续或不连续分布的第二相显著降低了合金的冲击韧性。     

不同固溶温度对双相不锈钢σ相析出及冲击韧性的影响

采用金相显微镜、扫描电镜、能谱分析、室温冲击等方法,研究了不同固溶温度下2205双相不锈钢σ相析出行为以及对冲击性能的影响,用于指导双相不锈钢的热加工工艺.结果表明:在750～ 900℃时,有σ相析出,析出位置集中在α/γ相界上.随着固溶温度的升高,σ相析出尺寸变大,析出量呈先增多再减少,σ相析出的鼻尖温度范围在850 ～ 900℃之间.σ相析出使2205双相不锈钢冲击韧性急剧下降,随固溶温度的升高,冲击韧性持续降低,900℃时冲击韧性最差,仅有38 J,因此双相不锈钢在热加工过程中应尽量避免在σ相析出温度范围内停留.     

热处理工艺对Mg-5Y-3Nd-1Gd-0.4Zr镁合金冲击韧性的影响

采用冲击实验研究了热处理工艺对Mg-5Y-3Nd-1Gd-0.4Zr镁合金U型缺口和无缺口试样的冲击韧性的影响,同时研究了时效时间对于时效态样品冲击性能缺口敏感性的影响。结果表明:固溶处理后合金的冲击韧性最高,断口形貌具有韧脆混合断裂特征,而时效后合金的冲击韧性迅速降低,断口形貌呈现脆性断裂的特征。这是由于固溶处理后合金的组织为单相组织,晶粒间和晶粒内协调性好,而时效处理后组织中析出大量第二相,在冲击变形过程中这些第二相阻碍位错运动,导致材料强度提高而韧性迅速降低。随着时效时间的延长,合金的室温缺口敏感性几乎不发生变化。当冲击温度提高到200℃时,缺口敏感性相对室温增加,这是由于存在缺口时,冲击过程几乎不发生塑性变形。提高实验温度,有缺口试样的冲击韧性增幅比无缺口试样的冲击韧性增幅要小的多,试样缺口敏感性也会增大。     

固溶温度对06Cr25Ni2奥氏体耐热钢微观组织和力学性能的影响

以热轧态06Cr25Ni20奥氏体耐热不锈钢为研究对象,采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM),结合硬度检测和拉伸试验等手段,研究了固溶温度对该材料微观组织和力学性能的影响。结果表明,热轧态耐热奥氏体不锈钢加工硬化严重、塑韧性差;固溶处理后其强度和硬度均下降,塑韧性则明显提高;随着固溶温度的升高,晶粒的方向性消除,晶粒尺寸变小且显微组织更为均匀,晶界上分布的Cr23C6相逐渐减少且消失;热轧态和1 000℃固溶处理后的室温拉伸断口呈脆性断裂特征,而经1 050℃以上固溶处理后,室温拉伸试样断口呈韧性断裂特征。     

X90高强管线钢母材及焊缝的冲击韧性

利用OM、SEM、TEM、EDS、EBSD及Charpy冲击实验对试制的X90钢级螺旋埋弧焊管母材和焊缝冲击断口形貌、近断口区微观组织特征、夹杂物成分、晶粒取向特征、大/小角度晶界占比及低温冲击韧性进行了研究。结果表明,在-10℃下,母材平均冲击功值达314 J,焊缝仅为157 J,母材冲击韧性远优于焊缝。母材试样近断口区显微组织为细小针状铁素体(FAF)+板条贝氏体(LB)+多边形铁素体(QPF)+少量M-A组元,M-A组元呈颗粒状,平均粒径约0.3μm,有效平均晶粒尺寸为2.3μm,大角度晶界比列为91.04%;焊缝试样近断口区组织为AF+QPF+M-A组元+少量先共析铁素体(PF),M-A组元弥散分布,形态多样,平均尺寸1.0~2.0μm,有效平均晶粒尺寸为3.5μm,大角度晶界比列为80.4%。晶粒尺寸粗大、大角度晶界占比偏低和大尺寸尖角型M-A组元是导致焊缝冲击韧性差的主要原因,而大尺寸密集型夹杂物分布使焊缝有更差的冲击韧性。     

固溶时效处理对TC11钛合金组织与 冲击性能的影响

对TC11钛合金进行固溶时效处理,通过光学显微镜、XRD以及冲击性能测试等,研究固溶时效处理后该合金微观组织与冲击性能的关系。结果表明：合金经955℃固溶处理后,组织由α_p相与α″相构成,α_p相形貌以等轴状和长条状为主,经1015℃固溶处理后,组织由α’相与α″相构成,α’相形貌呈细小针状,2组固溶条件下的合金再经时效处理后,组织中均出现β_T,并析出α_s相。合金的冲击韧性值在仅经955℃固溶处理后最大,其最大冲击韧性为22 J/cm²,经时效处理后,2组合金的冲击韧性值均随着时效温度升高而降低。当固溶温度为955℃时,断口形貌呈现韧性断裂特征,经时效处理后,断口形貌中出现二次裂纹。当固溶温度为1015℃时,断口形貌呈现脆性断裂特征,经时效处理后,断口形貌除二次裂纹外,有空洞出现。     

冷变形和固溶温度对HR3C钢中σ相析出行为的影响

结合HR3C钢制备工艺,综合研究冷变形和固溶处理工艺对其在时效过程中σ相的析出动力学和相关力学性能的影响。结果表明:冷变形和固溶温度均对该钢中σ相的析出有着较大的影响,变形量的增加会促进σ相的时效析出,升高固溶处理温度有助于抑制HR3C钢中σ相的析出行为,但却在一定程度上增大晶粒尺寸。σ相析出量随时间延长先缓慢增加,后快速析出,最后达到稳态值约5.7%(体积分数)。变形量的增加使HR3C钢时效过程中冲击韧性显著降低,而固溶温度的升高虽然增加了固溶态试样的冲击韧性但降低了时效过程中的冲击韧性。     

焊接热循环对T92钢组织脆化的影响

采用Gleeble—3800热模拟试验机对T92钢进行不同峰值温度的焊接热循环试验,并对试验试样进行室温冲击韧性试验.借助光学显微镜分析其微观组织,用扫描电镜观察其冲击试样断口形貌特征.结果表明,T92钢焊接加热温度在900℃以上易因奥氏体晶粒粗大导致其组织脆化,断口呈现典型的准解理形貌特征,而在900℃以下的焊接加热仍能保持较好的室温冲击韧性,断口呈现均匀细小的韧窝断口特征;T92钢中高含量的强碳、氮化物形成元素高温状态重新固溶后,在奥氏体中的扩散速度滞后于晶界的迁移速度,进而产生过饱和的室温组织是引起组织脆化的直接原因.     

热轧及热处理对Mg-Y-Nd合金组织的影响

考察热轧工艺及随后热处理对Mg-Y-Nd合金组织演变的影响。结果表明：低温(＜500℃)轧制时,大量稠密析出相的出现致使轧制性能极大地降低且组织难以细化;在固溶温度下轧制(525℃)时,晶粒极易粗化;当轧制温度略低于固溶温度时,轧制过程中会析出弥散的第二相粒子。这些粒子的存在没有恶化轧制性能且有效地钉扎晶界并抑制高温下再结晶晶粒的粗化。该合金的较佳轧制工艺如下：轧制温度为500℃、每道次轧制变形量为10%且总轧制变形量70%。热轧后,材料获得平均晶粒尺寸为30μm左右的组织,并产生较强的基面织构。固溶处理1h可有效地消除位错并维持细晶和基面织构。进一步增加固溶时间,晶粒发生粗化且织构变得分散。相比于均匀化态,经T6处理的热轧态Mg-Y-Nd合金的屈服强度提高176 MPa。     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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).     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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