基于人工神经网络的铜合金时效性能研究

利用神经网络对Cu-Cr-Zr合金时效温度、时间与硬度和电导率样本集进行学习，采用改进的BP网络算法—Levenberg-Marquardt算法，建立了时效强化工艺BP神经网络模型。预测结果表明：该BP神经网络可以充分挖掘样本蕴含的领域知识，可以对材料性能进行有效预测和分析。     

添加Si和Al的Cu-9Ni-2.5Sn合金的热处理工艺

对同时添加Si和Al的Cu-9Ni-2．5Sn合金进行了热处理工艺试验。通过金相、透射电镜观察其组织，并对其硬度、电导率进行了测量。分析结果表明，经添加Si和Al的Cu-9Ni-2．5Sn合金宜采用热轧(960℃～700℃)空冷 冷轧(变形量90％) 时效(480℃)的热处理工艺。经此工艺处理后，合金在保持硬度不变的同时，其电导率显著提高。     

利用神经网络建立快速凝固Cu-Cr-Zr合金时效知识库

根据人工神经网络(ANN)的BP(back propagation)算法，建立了快速凝固Cu-Cr-Zr铜合金时效温度和时间与硬度和导电率的神经网络映射模型。预测值与实际情况吻合良好，硬度和导电率最大误差分别为4．1％和1．9％。通过对样本集的学习，建立了快速凝固时效工艺知识库，对预测和控制该工艺性能非常有益。     

时效参数和变形量对Cu-Cr-Zr-Mg合金组织和性能的影响

研究了时效参数和变形量对Cu-0．3Cr-0．15Zr-0．05Mg合金组织与性能的影响。结果表明：该合金经920℃固溶1h后在470℃时效4h可获得较高的电导率和硬度，时效过程中析出相为体心立方Cr相和CuZr。变形可以加速第二相的析出，合金经60％变形后在500℃时效15min电导率可达70．49% IACS，而固溶后直接时效仅为43．05％IACS；这时硬度也比固溶后直接时效提高70～80HV。     

CuNiCoBe合金应变时效相变动力学分析

研究了固溶后应变时效处理对CuNiCoBe合金的电导率和硬度的影响。通过测量合金冷变形后恒温时效过程中的硬度和电导率变化,并根据电导率与新相的转变量之间的内在关系,计算出时效过程中新相的转变比例,推导出不同冷变形量、不同温度下描述CuNiCoBe合金时效时的新相体积分数与时效时间关系的Avrami经验方程及不同应变时效处理工艺下计算电导率随时效时间变化的电导率方程。     

Cu-Cr-Fe-Ni合金形变热处理过程中的组织与性能

采用非真空熔炼并经热轧—固溶—冷轧—时效热处理工艺制备Cu-0.59Cr-0.078Fe-0.081Ni合金板,探究热处理和冷变形对合金显微组织、电导率和硬度的影响。结果表明:Cu-Cr-Fe-Ni合金大气熔铸后呈明显的枝状晶组织,经固溶处理后合金发生再结晶,硬度和电导率都相应的降低,分别为65.9 HV0.2、41.7%IACS;经过冷变形处理后合金的硬度显著提高,变形量达90%时,合金的硬度高达144.7 HV0.2;合金变形后在450 ℃时效的过程中硬度先增加后减少,变形量为60%时,时效30 min达到峰时效,此时硬度、电导率分别为155.5 HV0.2、71.4 %IACS。     

La，Fe（或Co）／Ti对Cu-Cr-Zr合金时效特性的影响

研制了新型集成电路引线框架Cu-Cr-Zr系列合金，通过电导率、硬度、抗拉强度测试以及透射电镜观察，考察了微量合金元素La，Fe／Ti，Co／Ti元素以及时效工艺对合金性能的影响。结果表明：稀土元素La可以改善A合金(Cu-Cr-Zr-Zn)的硬度及导电率；加入Fe／Ti，Co／Ti元素，大大提高了合金的强度和硬度，并使其时效的强度及硬度峰值延后。在970℃固溶处理、70％冷变形及不同温度时效2h后，A合金(Cu-Cr-Zr-Zn)及B合金(Cu-Cr-Zr-Zn-La)在450℃时达到硬度和强度峰值，分别为HV1770MPa和525MPa及HV1840MPa和554MPa，电导率分别为78％和80％IACS；在970℃固溶处理，60％冷变形，500℃时效2h，50％冷变形及不同温度2次时效2h后，C合金(Cu-Cr-Zr-Zn-Fe-Ti-La)及D合金(Cu-Cr-Zr-Zn-Co-Ti-La)在450℃时达到硬度和强度峰值，分别为HV2120MPa，683MPa及HV2040MPa和651MPa，电导率分别为65％和70％IACS。     

热变形后时效工艺对Cu-0.92Cr合金组织和性能的影响

采用热变形+固溶+热变形+冷变形+时效工艺制备了Cu-0.92Cr合金试样,测试了试样的硬度和电导率,并进行了微观组织观察,研究了热变形后时效工艺对Cu-0.92Cr合金组织和性能的影响.结果表明,在试验参数范围内,随着时效温度的升高和时间的延长,合金的硬度逐渐下降,电导率升高.在420 ℃×6 h时效后,合金硬度(HB)为130.3,电导率可达52.49 MS/m.组织观察表明,经时效后析出相为具有面心立方结构、晶格参数为0.424 nm的化合物,颗粒大小约为4～15 nm,颗粒间距为10～30 nm.     

基于神经网络的Cu-Ni-Si-Cr合金时效性能预测研究

利用人工神经网络对Cu-Ni-Si-Cr变形合金时效工艺参数与时效后性能样本集进行学习,建立了合金时效后的性能关于时效温度、时间和变形量等参数的非线性映射模型。模型采用改进的BP算法kvenberg-Marquardt算法。结果表明：所建立的神经网络模型具有较高的精度及良好的泛化能力,可对Cu-Ni-Si-Cr合金时效后的性能进行有效的预测和分析。     

基于BP神经网络算法的耐磨钢热处理工艺优化

以耐磨钢牌号、淬火温度、淬火冷却方式、回火温度和回火冷却方式作为输入层参数,以硬度作为输出层参数,采用BP神经网络算法构建了耐磨钢热处理工艺优化的BP神经网络模型,并进行了模型的预测和应用验证。结果表明,该模型的输出参数平均相对预测误差为2.2%,具有较好的预测能力和较高的预测精度。与生产线现用工艺相比,采用BP神经网络模型优化工艺热处理后的NM360、NM400、NM500耐磨钢的磨损体积分别减小26%、26%、28%。     

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.     

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).     

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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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.