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。     

Prediction and analysis of the aging properties of rapidly solidified Cu-Cr-Sn-Zn alloy through neural network

It is known that the strength of a metal can be successfully improved by rapid solidification. The hardness of the rapidly solidified Cu-Cr-Sn-Zn alloy is much higher than that of the solution heat-treated and aged alloy. In this study, multiple-layer, feed-forward, artificial neural network (ANN) modeling has been used to study the hardness and electrical conductivity behavior of a rapidly solidified Cu-Cr-Sn-Zn alloy. The ANN model shows how the aging parameters influence the hardness and electrical conductivity of a rapidly solidified Cu-Cr-Sn-Zn alloy. The ANN modeling also provides encouraging predictions for information not included in the trained set samples, indicating that a backpropagation network is a very useful and accurate tool for property analysis and prediction.     

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…     

基于人工神经网络的铜合金形变热处理工艺和性能

利用神经网络对Cu-Cr-Zr合金变形量、时效温度和时间与硬度和电导率样本集进行训练和学习，采用改进的BP网络算法-Levenberg—Marquardt算法，建立了形变热处理工艺BP神经网络模型，得出了具有较高综合性能的最佳工艺参数：在80％变形量，450-480℃，2～5h形变热处理条件下，硬度和电导率分别可达HV150～157和74％～77％(IACS)。     

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

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

镁硅复合微合金化对高强高导铜铬锆合金时效过程的影响

采用中频感应熔炼炉制备了Cu-0.7Cr-0.15Zr和Cu-0.7Cr-0.15Zr-0.05Mg-0.02Si两种合金,研究了Mg、Si复合微合金化对Cu-Cr-Zr合金时效工艺参数、性能与析出动力学的影响。结果表明：Mg、Si复合微合金化提高了Cu-Cr-Zr合金的最佳时效温度,延长了保温时间,Cu-0.7Cr-0.15Zr合金的最佳时效工艺为410 ℃时效8h,Cu-0.7Cr-0.15Zr-0.05Mg-0.02Si合金的最佳时效工艺为430 ℃时效14 h。Mg、Si复合微合金化提高了Cu-Cr-Zr合金的强度与导电率,Cu-0.7Cr-0.15Zr合金最佳工艺条件下的强度为570 MPa、电导率为79.1%IACS;Cu-0.7Cr-0.15Zr-0.05Mg-0.02Si合金最佳时效工艺条件下的强度为595 MPa、电导率为80.4%IACS。Mg、Si复合微合金化改变了Cu-Cr-Zr合金Avrami相变动力学方程,减缓了时效析出过程。     

Microstructures of rapidly solidified Al-In immiscible alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｍａｎｙｂｉｎａｒｙｉｍｍｉｓｃｉｂｌｅｓｙｓｔｅｍｓｗｉｔｈａｍｉｓｃｉｂｉｌｉｔｙｇａｐｗｈｉｃｈｈａｖｅｂｅｅｎｉｄｅｎｔｉｆｉｅｄａｓｄｅｓｉｒ ａｂｌｅｆｏｒｍａｎｙａｐｐｌｉｃａｔｉｏｎｓ ,ｓｕｃｈａｓｅｎｇｉｎｅｅｒｉｎｇａｎｄｅｌｅｃｔｒｏｎｉｃｍａｔｅｒｉａｌｓ ,ｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓｕｐｅｒｃｏｎｄｕｃ ｔｏｒｓ,ａｎｄｓｅｌｆ ｌｕｂｒｉｃａｔｉｏｎｂｅａｒｉｎｇｓ[1～ 3] .Ｈｏｗｅｖｅｒ ,ｔｈｅｆａｂｒｉｃａｔｉｏｎｏｆｓｕ…     

Cu-Cr-Zr系合金非真空熔炼过程的热力学分析

对Cu-Cr-Zr系合金非真空熔炼过程进行热力学分析,分别计算Cu、Cr和Zr等合金组元与炉气、坩埚、炉衬和炉渣反应的吉布斯自由能变化,分析合金熔炼过程中相关反应的可能性,并对部分分析结果进行实验验证。结果表明,在熔炼温度下,炉气中微量氧气和氮气都能与合金组元中的铬和锆发生化学反应而使其烧损;金属氧化物ZrO2和MgO等对于铬和锆具有良好的化学稳定性,可以作为熔炼Cu-Cr-Zr系合金的坩埚和炉衬材料。     

热处理对Cu-Cr-Zr合金抗拉强度的影响

研究了固溶和时效热处理对Cu-Cr-Zr合金抗拉强度的影响.结果表明：热处理对Cu-Cr-Zr合金抗拉强度有较大的影响,当CuCrZr合金经1040 ℃固溶处理后再经480 ℃保温4 h时效处理可获得较高的抗拉强度.     

快速凝固镁合金开发原理及研究进展

介绍快速凝固镁合金材料研究与开发的物理冶金原理及发展历程。在开发原理中着重介绍快速凝固镁合金的镁基固溶体扩展、新型弥散合金相的形成、晶粒及显微组织细化以及合金钝化等基础理论。在这些研发理论基础上，进一步阐述镁合金雾化快凝、模冷淬火和表面重熔这3种典型的快速凝固制备技术，举例说明了这3种快速凝固技术制备的多种镁合金的各项性能及显微组织特征。综合评价快速凝固技术制备镁合金材料的优势，说明快速凝固技术是开发新型镁合金材料，扩展镁合金在工程材料中应用的重要且具有发展前途的制备技术。     

Analysis of precipitation in a Cu-Cr-Zr alloy

Precipites in Cu-0.42%Cr-0.21%Zr alloy were analyzed by using scanning electron microscope （SEM）, energy dispersive X-ray spectroscopy （EDXS） and transmission electron microscope （TEM）. After the solid solution was performed at 980℃ for 2 h, water-quenched and aged at 450℃ for 20 h, the precipite had a bimodal distribution of precipitate size. The coarse precipitates are pure Cr and Cu5Zr, the dispersed fine precipitate is CrCu2（Zr, Mg） and pure Cr ranging from 1 to 50 nm. The coarse phases formed during solidification and were left undissolved during solid solution. The fine precipitates are the hardening precipitates that form due to decomposition of the supersaturated solid solution during aging.     

快速凝固新型Au-Ag-Ge合金薄带的制备

采用单辊快速凝固法制备了Au-19.25Ag-12.80Ge合金薄带。利用TEM方法对合金薄带的显微组织进行了观察分析,根据热传输平衡方程对快速凝固过程冷却速率进行估算。结果表明:辊面线速度在18~24 m/s范围内时,快速凝固冷却速率可达8.93×105~1.293×106K/s,随着快速凝固冷却速率的增加,合金薄带厚度有所减小;单辊快速凝固工艺的冷却速率对合金薄带的显微组织有重要影响,由于快速凝固工艺增加了材料的固溶度,减小了成分偏析,细化了晶粒,因此显微组织更加均匀细小,形成了纳米晶,快速冷却工艺在金属熔液内垂直于辊轮方向上产生的冷却速度梯度,造成了晶粒内部应力集中现象的产生。     

快速凝固高硅铝合金粉末的热挤压过程

通过分析快速凝固高硅铝合金末在热挤压过程中的密度、微观组织和相结构的变化，对粉末热挤压成形机理进行了探讨，结果表明，快速凝固高硅铝合金粉末热压过程分为2个阶段，即填充挤压阶段和稳态渡动阶段，粉末生坯的致密化主要有在第一阶段完成，粉末颗粒中初晶Si相受到加热长大和挤压破碎两方面的综合作用，最终得到的挤压材料中的Si颗粒与原始粉末相比没有明显的相比，合金的相组成在挤压前后 有发生变化，快速凝固合 组织结构特征基本得以保留。     

Morphology and microstructure of rapidly solidified tin-lead alloy powders

Sn60Pb40 al oy powders were fabricated using the planar flow casting （PFC） atomization process. By using OM, SEM and EPMA, the characteristics of the morphologies and microstructures of the powders have been investigated. It is observed that the environment of ambient gas in the atomization box has great effects on the morphology of the al oy powders. The microstructures of Sn60Pb40 al oy powders produced by the PFC atomization process are completely composed of eutectic, which is made up of both oversaturated αsolid solution and β solid solution. The microstructures of smal size powders are extraordinarily undeveloped dendritic eutectic, in which the large majority of the α phase appears nearly spherical, evidently since the cooling rate is higher and the under-cooling is larger. As for the large size powders, since the cooling rate and undercooling are relatively low, lamel ar α phase apparently increases in the eutectic microstructures of these powders, and there is even typical lamellar eutectic structure clearly observed in some micro-areas. After remelting tests by DTA, the microstructures of smal size powders are transformed, which become composed of large crumby α phase and eutectic （α＋β）, while those of large size powders change into classical tin-lead structures of primary α phase plus lamellar eutectic （α＋β）. By studying the microstructures of tin-lead alloy powders, a model has been proposed to predict the microstructure formation of Sn60Pb40 al oy powders.     

Cu-0.8Cr-0.2Zr合金固溶时效后的组织与性能研究

通过检测Cu-Cr-Zr合金在固溶时效过程中硬度、电导率的变化及显微组织的观察,研究不同热处理条件对该合金组织和性能的影响。试验结果表明：固溶时效后在合金基体中能得到大量的孪晶组织及细小的析出粒子,在两者综合作用下,合金的组织和性能得到极大的改善。合金在980℃固溶、450℃时效3 h后性能最佳。合金的硬度为111.5 HBS,相对电导率为78.42%IACS。     

快速凝固高硅铝合金加热过程中的组织转变

利用气雾化法制备高硅铝合金粉末,采用光学显微镜(OM)、扫描电镜(SEM)等现代测试手段,分析快速凝固高硅铝合金不同粒度粉末微观组织和结构特征,研究在不同加热温度和保温时间条件下针状富铁相的转变特性及β-Si相的粗化行为。结果表明:快速凝固高硅铝合金组织主要以基体上分布有大量细小的颗粒状和针状相为特征,合金粉末在加热过程中,随着温度的升高和保温时间的延长,颗粒β-Si相有粗化趋势,针状非平衡富铁相转变为棒状或颗粒状平衡相。通过台阶式连续加热模拟试验可获得针状相基本消失且颗粒β-Si相未发生明显粗化的组织。     

快速凝固Cu-Sn合金的组织形态及相结构

研究快速凝固Cu-20%Sn亚包晶合金的相结构、晶体生长行为和组织特征,分析冷却速率与组织形成之间的相关规律。结果表明:在急冷快速凝固条件下,合金的包晶转变和共析转变均受到抑制,形成了以亚稳的Cu5.6Sn金属间化合物为主相的快速凝固组织;随着冷却速率的增大,-αCu相含量减少,Cu5.6Sn相数量显著增多;晶体生长的方向性增强;Cu5.6Sn生长方式由小平面向非小平面生长转变,组织形态由粗大板条状向细密柱状转变。TEM分析表明:在Cu5.6Sn晶内存在大量的位错塞积及孪晶;孪晶之间相互平行,间距约25~80 nm;随冷却速率的增大,位错密度增大,孪晶数量增多。     

固溶时效处理对快速凝固LAZ941-0.5Y镁锂合金组织和硬度的影响

通过光学显微镜(OM)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和显微硬度仪等研究了固溶时效处理对快速凝固Mg-9Li-4Al-1Zn-0.5Y(LAZ941-0.5Y)镁锂合金的组织和硬度的影响.结果 表明:经固溶处理后,合金的显微组织粗化,第二相主要弥散分布在α-Mg相和β-Li相中及它们的相界...     

固溶处理对Cu-Cr-Zr合金组织与性能的影响

对热轧态Cu-1.0Cr-0.1Zr合金在电阻炉中进行了不同温度不同保温时间的固溶处理,并对固溶后合金的组织与性能进行了检测,分析了固溶温度与时间对该合金组织性能的影响。结果表明:固溶后合金组织性能由回复、再结晶、未溶粒子回溶与晶粒长大综合影响;随固溶温度升高,合金的硬度先大幅下降,后不断上升,而导电率不断下降;随固溶时间的延长,合金的硬度呈抛物线升高并趋于平缓的趋势,导电率的变化则与之相反。在固溶温度为950 ℃,固溶时间为120 min时,固溶基本完成,此时硬度为58.9 HBS,导电率为50%IACS。     

Decomposition processing and precipitation hardening of rapidly solidified Al-Cr-Y-Zr alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＦｏｒｌａｓｔｔｗｏｄｅｃａｄｅｓｒａｐｉｄｌｙｓｏｌｉｄｉｆｉｅｄＡｌ Ｃｒ Ｚｒ( Ｍｎ)ｈｅａｔ ｒｅｓｉｓｔａｎｔａｌｕｍｉｎｕｍａｌｌｏｙｓｙｓｔｅｍｈａｓｂｅｅｎｐａｉｄａｐｕｂｌｉｃａｔｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｉ