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。     

Establishing the knowledge repository of rapidly solidified aging Cu-Cr-Zr alloy on the artificial neural-network

The non-linear relationship between parameters of rapidly solidified aging processes and mechancal and electrical properties of Cu-Cr-Zr alloy is available by using a supervised artificial neural network (ANN). A knowledge repository of rapidly solidified aging processes is established via sufficient data learning by the network. The predicted values of the neural network are in accordance with the tested data. So an effective measure for foreseeing and controlling the properties of the processing is provided.     

Simulation of aging process of lead frame copper alloy by an artificial neural network

1　INTRODUCTIONThefunctionsofleadframeinelectronicpackingareprovidingchannelsforelectronicsignalsbetweendevicesandcircuits ,andfixingdevicesoncircuitboards.Leadframealloysarerequiredtohavehighstrengthandgoodformabilityaswellashighelectri calandthermalconductivity .Cu basealloysarethemostpopularleadframealloysandareusedinplasticpackagingapplicationduetotheirhighthermalandelectricalconductivityaswellashighstrength[13] .Theaginghardening processinfabricationofleadframecopperalloymakesitpossi…     

EFFECT OF COLD WORKING ON THE AGING PROPERTIES OF Cu-Cr-Zr-Mg ALLOY BY ARTIFICIAL NEURAL NETWORK

A developmental research has been carried out to deal with the high performance of Cu-Cr-Zr-Mg lead frame alloy by artificial neural network (ANN). Using the cold working to assist in the aging hardening can improve the the hardness and electrical conductivity properties of Cu-Cr-Zr-Mg lead frame alloy. This paper studies the effect of different extent of cold working on the aging properties by a supervised ANN to model the non-linear relationship between processing parameters and the properties. The back-propagation (BP) training algorithm is improved by Levenberg-Marquardt algorithm. A basic repository on the domain knowledge of cold worked aging processes is established via sufficient data mining by the network. The predicted values of the ANN coincide well with the tested data.So an important foundation has been laid for prediction and optimum controlling the rolling and aging properties of Cu-Cr-Zr-Mg alloy.     

Evolutionary artificial neural network approach for predicting properties of Cu- 15Ni-8Sn-0.4Si alloy

A novel data mining approach, based on artificial neural network（ANN） using differential evolution（DE） training algorithm, was proposed to model the non-linear relationship between parameters of aging processes and mechanical and electrical properties of Cu-15Ni-8Sn-0.4Si alloy. In order to improve predictive accuracy of ANN model, the leave-one-out-cross-validation （LOOCV） technique was adopted to automatically determine the optimal number of neurons of the hidden layer. The forecasting performance of the proposed global optimization algorithm was compared with that of local optimization algorithm. The present calculated results are consistent with the experimental values, which suggests that the proposed evolutionary artificial neural network algorithm is feasible and efficient. Moreover, the experimental results illustrate that the DE training algorithm combined with gradient-based training algorithm achieves better convergence performance and the lowest forecasting errors and is therefore considered to be a promising alternative method to forecast the hardness and electrical conductivity of Cu- 15Ni-8Sn-0.4Si alloy.     

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。     

GA-BP神经网络在AgCuNi电接触材料的性能预测研究

本文针对现有AgCuNi系电接触材料对硬度和导电率预测方法不足等问题,采用遗传算法对BP神经网络的权值和阈值优化,加快了算法的收敛速度,建立了基于遗传算法优化的BP神经网络AgCuNi系电接触材料的硬度和导电率预测模型。训练精度和实际测试精度分别达到了0.98和0.89,误差9.18%。研究结果表明,本文建立的BP神经网络预测模型,有助于提高合金的成分设计效率,提高银合金电接触材料的开发效率。     

Coherent strengthening of aging precipitation in rapidly solidified Cu-Cr alloy

1INTR0DUCTIONHavinghighstrengthandgoodelectricalandthermalconductivities,Cu-Cralloysareusedinanumberofengineeringapplications,suchaselectricresistanceweldingelectrode,thelinertubeofcontinuouscastingcrystallizer,integrat-edcircuitleadframe,stiltwire0felectricloco-motive.However,higherstrengthismoreandmorerequiredforc0pperalloyswiththerapiddevelopmentofelectronicindustry.Forexam-ple,tensilestrengthdb>600MPa,hardnessHV>180andconductivity>80%(IACS)arede-mandedforleadframematerialsinverylar…     

快速获得7055铝合金淬火敏感温度区间的新方法及机理（英文）

采用一种省时、节约资源的变温热处理(ATHT)新方法，基于硬度与电导率，获得喷射沉积7055铝合金的淬火敏感温度区间。此外，通过透射电子显微镜(TEM)表征ATHT期间的显微组织演变。研究表明，7055合金的ATHT是一个溶质原子随着温度的升高而析出和再溶解的过程。当温度达到200℃时，合金的硬度急剧增加，电导率适当增加。随着温度升高到400℃以上，电导率从峰值迅速下降，表明溶质原子回溶加速，同时，在基体内η’强化相逐渐转变成η平衡相。通过对硬度曲线和电导率曲线的分析，得出当前合金淬火敏感性温度范围为200～400℃，这与传统分级保温法测得的结果一致。     

Al-Er-Cu合金架空导线的导电性能

通过导电率、硬度测试方法研究了Al-Er-Cu合金在等时时效与等温时效过程中的性能变化规律,利用透射电镜(TEM)、能谱分析(EDS)观察了合金析出相的析出及生长规律。结果表明:随着时效温度升高,整体上同一合金的导电率与硬度峰值出现时间均提前;300 ℃时效时,Al-Er-0.22Cu合金已经析出大量纳米级弥散相,析出强化了合金强度,提高了导电率,时效2 h时达到导电率峰值60.15%IACS,10 h达到硬度峰值43.1 HV0.05,Al-Er-0.22Cu合金在拥有高导电率的同时保持了较好的硬度。     

快速凝固Cu—Cr合金时效析出的共格强化效应

采用单辊快速凝固的方法制备Ｃｕ－Ｃｒ合金微晶薄带,经适当的时效处理,可以在导电率不降低的前提下,显著提高合金的强度和硬度,强度和硬度的提高主要是由晶粒细化和共格弥散析出强化所造成,共格硬化效果与采用Ｇｅｒｏｌｄ公式计算的结果非常接近,与常规固溶处理的Ｃｕ－Ｃｒ合金相比,峰值硬度提高了１．６倍,其中２７％由细晶强化产生,７３％则由时效析出的共格强化提供,固溶强化和空位强化对快速凝固Ｃｕ－Ｃｒ合金强度     

一种新型Al-Zn-Mg-Cu高强铝合金的析出行为及性能(英文)

对一种新型高强Al-Zn-Mg-Cu合金在单级时效过程中的硬度、强度、电导率变化及相应的析出行为进行系统的研究。结果表明,电导率随着时效温度的升高和时效时间的延长而不断增高。在时效开始阶段,硬度和强度随着时效的进行迅速升高并达到峰值。在120°C时效时,硬度和强度到达峰值后保持稳定,主要的析出相是GPI区、GPII区和η′相。在120°C长时间(直至24h)时效后,GPI区和GPII区仍能稳定存在。在160°C时效时,硬度和强度到达峰值后迅速下降。与120°C时效相比,在160°C时效时,析出过程更快。在160°C时效1h后,未观察到GPI区及GPII区的存在,主要的析出相为η′相。在160°C时效24h后,主要的析出相为η相。     

Effect of different quenching processes following solid-solution treatment on properties and precipitation behaviors of 7050 alloy

The effects of quenching in different ways following solid-solution treatment on properties and precipitation behaviors of 7050 alloy were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), hardness and electrical conductivity tests. Results show that after quenching in different ways, electrical conductivity of the alloy decreases rapidly in the first 48 h of natural aging. The electrical conductivity of 7050 alloy in natural aging state is determined by the size and density of GP zones, and the size of GP zones is the main factor. After natural aging for 70 d, the size of GP zones is 1.8–2.6 nm in matrix of the immersion quenched sample and it is 1.4–1.8 nm in matrix of both water mist and forced air quenched samples. After natural and artificial peak aging, the hardness of the water mist quenched sample is HV 193.6 and its electrical conductivity is 30.5% (IACS) which are both higher than those of the immersion quenched sample. Therefore, water mist quenching is an ideal quenching method for 7050 alloy sheets after solid-solution treatment.     

Cu-Cr合金强化机制研究及其对导电性能的影响

采用真空铸造-固溶处理-冷轧-时效处理工艺制备了Cu-0．8％Cr合金。利用金相显微镜、透射电镜、选取电子衍射、硬度和电导率测试等手段考察了合金在不同处理状态下的组织和性能，定量分析了不同强化方式对合金硬度及导电性能的影响。结果表明：与固溶强化相比，析出强化方法更能有效强化合金，对导电性能影响也更小；形变强化能显著提高合金硬度，但对导电性能几乎无影响；大预变形、短时时效是合金获得较高综合性能的有效手段。     

电子封装材料过共晶硅-铝合金的组织特征和热性能(英文)

采用快速凝固制粉技术和粉末热压烧结技术制备55%Si-Al,70%Si-Al和90%Si-Al3种过共晶含量的硅铝合金。结果表明:雾化沉积是制备过共晶硅铝合金的有效的快速凝固工艺,采用该工艺获得的快速凝固硅铝合金粉末的尺寸小于50μm。快速凝固的硅铝合金粉末经过550°C和700MPa热压后,获得3种不同成分合金试样的相对密度分别为99.4%,99.2%和94.4%。作为电子封装材料,3种试样的热导率、热膨胀系数和电导率都可以满足应用要求。55%Si-Al合金的热膨胀系数随温度的变化最剧烈,但是该合金具有较好的热导率。90%Si-Al合金的热膨胀系数较小,但是其热导率最差,小于100W/(m·K)。70%Si-Al合金具备热沉材料所应具备的优良的热导率和热膨胀系数的综合性能。     

Single-aging characteristics of 7055 aluminum alloy

The microstructures and properties of 7055 aluminum alloy were studied at different single-aging for up to 48 h using hardness test, tensile test, electrical conductivity measurement, XRD and TEM microstructure analysis. The results show that at the early stage of aging, the hardness and strength of the alloy increase rapidly, the peak hardness and strength are approached after 120 ℃ aging for 4 h, then maintained at a high level for a long time. The suitable single-aging treatment of 7055 alloy is 480 ℃, 1 h solution treatment and water quenching, then aging at 120 ℃ for 24 h. Under those condition, the tensile strength, yield strength, elongation and electrical conductivity of the studied alloy are 513 MPa, 462 MPa, 9.5% and 29%（IACS）, respectively. During aging, the solid solution decomposes and precipitation occurs. At the early aging stage of 120 ℃, GP zones form and then grow up gradually with increasing ageing time. η′ phase forms after ageing for 4 h and η phase starts to occur after 24 h aging.     

镁与热处理对Al-4Si-(xMg)合金导电性及力学性能的影响

利用SEM、XRD、EDS、硬度计及电阻率测试仪等方法分析Mg元素和不同热处理对Al-4Si-(xMg)(x=0～1.5％,质量分数)系列合金导电率及硬度的影响.结果表明:随Mg添加量增加,铸态合金的导电率和硬度先增后减,最佳添加量为1.1％.Mg使铸态合金硬度显著增加,但恶化了其导电率.Al-4Si-(xMg)合金经...     

稀土金属Y对Cu-Cr合金硬度和导电率的影响

研究了稀土金属Y不同添加量和不同固溶时效处理工艺对Cu0．8Cr合金硬度和导电率的影响。结果表明，铸态Cu0．8Cr合金的硬度随Y含量的增加而升高；经过不同固溶时效后，硬度出现波动，其中Cu0．8Cr0．4Y可获得最高硬度。过量的Y能增加硬度，但会降低导电率，经固溶时效处理后导电率最高的合金为Cu0．8Cr0．1Y。     

固溶时效工艺对Cu-Ni-Co-Si合金组织和性能的影响

通过硬度和导电率的测量、光学显微镜和透射电镜(TEM),研究了固溶时效工艺对Cu-Ni-Co-Si合金组织和性能的影响。结果表明:经过950 ℃×30 min水淬+500 ℃×480 min随炉冷却后,Cu-Ni-Co-Si 合金得到良好的综合性能:硬度为243.55 HV3,导电率为42.24%IACS;添加少量的V有利于提高二次时效后合金的导电率,并且进行适当的一次时效对提高合金的导电率和硬度是有利的,可以使二次时效试样迅速获得良好的综合性能;Cu-Ni-Co-Si合金的主要强化相为盘状正交结构的δ-(Co,Ni)₂Si,过饱和固溶体析出的沉淀物均匀分布,但位错缠结始终存在,其中基体与析出相的位向关系为[001]_m//[110]_p, (010)_m //(001)_p。     

冷变形对表面弥散强化铜合金组织与性能的影响

以Cu2O为氧源,对Cu-Al合金平板试样进行了内氧化处理,使试样表面获得Al2O3弥散强化铜合金层,并进行了不同变形量的冷轧变形;测定了内氧化前后和冷变形前后试样硬度和导电率,并进行了微观组织观察。结果表明：内氧化处理后,合金表面硬度与合金导电率大幅度提高;随着变形量的增加,合金表面硬度值急剧升高,而电导率随着变形量的增加则略有下降。微观组织研究表明：内氧化后合金表面存在大量的纳米级Al2O3颗粒,使合金表面具有高的硬度;随着变形量的增加,位错密度升高,位错与第二相粒子的作用加剧,从而使合金表面的硬度进一步提高;同时由于Al2O3颗粒周围位错缠结的增多,增强了电子的散射作用,导致合金电导率随变形量增加呈下降趋势。