喷墨打印中的银导电墨水综述

介绍了应用在电子喷墨打印技术中的两枑导电银墨水：纳米颗粒墨水和金属有机先驱体墨水的组成体系、制备方法和性能影响因素;结合国外悁究前沿简要介绍了当前两枑墨水的悁究现状和发展方向。最后对两枑墨水的综合性能进行了对比,并指出了导电墨水未来的挑战。     

直接喷墨打印成形铁磁软磁材料的工艺研究

本文以羰基铁粉为原料,用DISPER-Y220为分散剂,制备出粘度为0.55Pa.s,流动性良好的料浆,以此料浆作为打印“墨水”,利用直接喷墨打印成形技术制备纯铁软磁材料制件。喷头直径分别以0.5mm、0.8mm和1.0mm打印零件,打印成形后通过脱脂和烧结制备出制件。结果表明：分散添加量为1wt%时,料浆粘度最低,随着固含量的增大,料浆粘度变大,随着剪切速率的增大,料浆表现为剪切变稀特征;喷头直径为0.8mm所打印的烧结体,表面粗糙度最低,其Ra为0.8μm;在1300℃保温2h烧结后,喷头直径为0.5mm的烧结体致密度最高,为96.3%,其磁饱和感应强度B_s达到1.53T,最大磁导率μ_max达到2630。     

Aging of Water-Soluble Formulations for Inkjet Printing of Functional Layers Based on Polyaniline

Protection of Metals and Physical Chemistry of Surfaces - The process of aging of water-soluble formulation based on polyaniline with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) complex was...     

高速喷墨数字印刷机恒温恒压供墨系统设计

为了进一步提升喷墨印刷设备的性能,对供墨系统进行了研究。在分析供墨系统功能需求的基础上,提出了供墨系统墨路、液路、气路的设计方案,从硬件和软件角度详细讨论了该恒温恒压、具备清洗、点墨等附加功能的机电气液一体化的供墨系统,并通过实验验证该系统的有效性。目前该系统已经在喷墨数字印刷设备上投入使用,取到了满意的效果。     

Improvement of Dry EDM Characteristics Using Piezoelectric Actuator

This paper describes improvement of the machining characteristics of dry electrical discharge machining (dry EDM) by controlling the discharge gap distance using a piezoelectric actuator. Dry EDM is a new process characterized by small tool electrode wear, negligible damage generated on the machined surface, and significantly high material removal rate especially when oxygen gas is used. However, the narrow discharge gap length compared with conventional EDM using oil as the dielectric working fluid results in frequent occurrence of short circuiting which lowers material removal rate. A piezoelectric actuator with high frequency response was thus introduced to help control gap length of the EDM machine. To elucidate the effects of the piezoelectric actuator, an EDM performance simulator was newly developed to evaluate the machining stability and material removal rate of dry EDM.     

喷墨打印制备LFP/Mxene阴极锂电池及其电化学性能

制备了MXene含量2%、3%、4%、5%、6%（质量分数）的磷酸铁锂(LFP)/Ti₃AlC₂(MXene)复合材料并将其制备成墨水,通过喷墨打印方法得到锂离子阴极电池,并研究MXene含量对LFP电化学性能的影响。结果表明,随着MXene含量的增加,LFP/MXene 复合材料的电化学性能先升高后降低。以4%MXene的添加剂制备得到的LFP/MXene 复合材料电化学性能测试最佳,其电容量达到181.2 mAh·g^-1,100次循环后其库仑效率为99.4%。MXene材料具有手风琴层状结构,使得磷酸铁锂的接触比增加,此外,MXene材料比石墨烯材料具有更多的官能团结构,有助于LFP的电化学性能改进。但如果MXene加入过多,MXene材料发生结块,会降低LFP/MXene 复合材料电化学性能。     

压电陶瓷在激光干涉错位散斑检测中的一些应用

对检测表面或检测构件施加振动激励以达到探测构件表层下缺陷的目的。将压电陶瓷元件接入适当的电压调节控制电路,利用压电陶瓷的逆压电效应原理,通过计算机程序可以让压电陶瓷元件发生随电压变化的微位移,电压的变化由程序设定,按应用场合的不同,可分别使压电陶瓷的微位移变成检测所需要的相移或振动。多次的实际检测结果表明,在一些航空材料粘接构件的激光干涉无损检测(NDT)中,压电陶瓷是目前人们实现相移和振动激励等特殊功能的最佳选择之一。     

压电驱动脉动混合可控合成金纳米粒子

在用柠檬酸钠作还原剂还原氯金酸的基础上,提出了一种压电驱动式脉动微混合可控合成金纳米粒子的制备方法。分析了金纳米粒子的合成机理及脉动微混合的工作原理。针对不同的浓度比(Na_3C_6H_5O_7:HAuCl_4)和脉动混合频率设计并开展了相关金纳米粒子可控合成试验,利用紫外可见分光光度计和透射电子显微镜对所得样品的光学特性、粒子粒径、粒子偏差及单分散性进行了表征,分析了浓度比和频率对试验结果的影响。结果表明:利用压电驱动式脉动微混合法,通过控制两相制剂的浓度比和脉动混合频率,一定程度上可以实现金纳米粒子的可控合成。     

采用3D打印技术开发柴油机气缸体铸造工艺

介绍了直列4缸柴油机气缸体的铸件结构及技术要求,分析了采用传统工艺生产铸件存在的问题。详细阐述了基于3D打印技术设计的一套组芯、造型工艺,替代传统的手工组芯造型方法。生产结果显示:铸件废品率为4.7%,生产验证过程质量稳定;金相组织和力学性能检测结果均符合技术要求;铸件尺寸、表面质量、气密性检测等按照相关规范检验合格,经内部检测,铸件表面粗糙度小于25μm。3D打印成型技术的使用,简化了操作过程,降低了生产难度,提高了生产效率,推动了汽车发动机新型气缸体的研发进度。     

Cold Gas-Sprayed Deposition of Metallic Coatings onto Ceramic Substrates Using Laser Surface Texturing Pre-treatment

Cold spraying enables a variety of metals dense coatings onto metal surfaces. Supersonic gas jet accelerates particles which undergo with the substrate plastic deformation. Different bonding mechanisms can be created depending on the materials. The particle–substrate contact time, contact temperature and contact area upon impact are the parameters influencing physicochemical and mechanical bonds. The resultant bonding arose from plastic deformation of the particle and substrate and temperature increasing at the interface. The objective was to create specific topography to enable metallic particle adhesion onto ceramic substrates. Ceramic did not demonstrate deformation during the impact which minimized the intimate bonds. Laser surface texturing was hence used as prior surface treatment to create specific topography and to enable mechanical anchoring. Particle compressive states were necessary to build up coating. The coating deposition efficiency and adhesion strength were evaluated. Textured surface is required to obtain strong adhesion of metallic coatings onto ceramic substrates. Consequently, cold spray coating parameters depend on the target material and a methodology was established with particle parameters (diameters, velocities, temperatures) and particle/substrate properties to adapt the surface topography. Laser surface texturing is a promising tool to increase the cold spraying applications.     

线阴极滚印式掩膜电解加工微坑阵列试验研究

目的 为了解决现有电解加工技术中难以使用同一装置在多种型面零件表面一次性大面积制备高精度微坑阵列的现状。方法 提出一种可用于多种型面零件批量加工微坑阵列的线阴极滚印式掩膜电解加工技术,设计了一种滚筒式掩膜复合线阴极的阴极工具装置,采用铜丝(直径500μm)作为阴极,图形化的聚氯乙烯(PVC)作为掩膜,在10%NaNO₃电解液、0.1 mm极间间隙条件下,在不锈钢304材料工件表面进行电解微坑试验,探究电压、阴极工具旋转速度、阴极尺寸对加工微坑阵列形貌的影响,通过超景深显微镜、扫描电子显微镜以及奥林巴斯显微镜对电解后的工件试样表面进行表面微观形貌观测。结果 选用10.5 V的电压、0.2 r/min的旋转速度可在工件表面加工出高精度、高一致性的微坑阵列,其微坑直径分布范围为402.8～440.3μm,深度范围为66.2～74.2μm,微坑粗糙度范围为0.42～0.83μm。与传统的圆环型阴极电解加工结果对比,线阴极电解加工出的微坑阵列直径偏离掩膜孔尺寸小、定域性高。结论 使用线阴极滚印式掩膜电解加工方法可在不锈钢304材料工件平面、内圆柱面及外圆柱面制备大批量、高精...     

B2FeAl合金晶格动力学的嵌入原子模型计算

应用改进分析型EAM模型，系统计算了B2FeAl合金的晶格动力学性能，包括晶格常数、形成热、弹性常数、声子谱、态密度、比热、德拜温度和热膨胀系数等，并将计算结果与已有实验数据及其他理论计算结果进行了比较。总的来说，仅从合金组成元素的性质出发，不涉及合金本身性质而构建的改进分析型EAM模型成功地描述了B2FeAl合金原子间的相互作用，所得计算结果与实验值符合很好。     

Sn-Zn钎料钎焊镁合金AZ31B接头的显微组织及力学性能

以Sn-Zn钎料对变形镁合金AZ31B进行了炉中钎焊,研究了变形镁合金AZ31B钎焊接头的微观结构与连接强度。采用XRD、SEM、EDS等仪器分析了钎焊接头的界面组织和钎缝物相,测试了钎焊接头的剪切强度与钎缝组织的显微硬度。结果表明,Sn-Zn钎料在钎焊过程中与母材AZ31B发生溶解与扩散作用,在钎缝中生成金属间化合物Mg2Sn和(β-Sn+Mg2Sn)共晶组织。钎焊接头中母材的显微硬度最低,Mg2Sn的显微硬度最高,钎焊搭接接头平均抗剪切强度达到48 MPa。钎焊搭接接头的主要断裂形式为沿晶脆性断裂,断裂主要发生在共晶组织和Mg2Sn相处。     

Effect of remelting process on characterization of air-plasma sprayed Fe67.5Ni23.5B9 alloy coatings onto 1Cr18Ni9Ti stainless steel

To develop a composite material with good mechanical and radiation shielding properties, the Fe–Ni–B (Fe_67.5Ni_23.5B₉, wt. %) coatings onto ₁Cr₁₈Ni₉Ti stainless steel substrate (SS, same as below) were prepared using air-plasma spraying (APS) technique in this work. A remelting process (1050 °C/2 h) was performed on the Fe–Ni–B coatings laminated composite under vacuum condition. The microstructure, phase composing, adhesion strength, Vickers hardness distribution and residual stress of Fe–Ni–B coatings before and after the remelting process were contrastively characterized. The results show that the remelting process decrease the coating defects and make the coating more cohesive and stable. The element diffusion and new compounds formation within the coating and interface area improves the adhesion and thermal fatigue of Fe–Ni–B coatings. In addition, the drop of variability of Vickers hardness data and residual stress level qualitatively identify that the Fe–Ni–B coatings possess more consistent microstructure and mechanical integrity after the remelting process.     

Al基钎料钎焊镁合金AZ31B接头的显微组织及力学性能

为了连接变形镁合金AZ31B,以Al基钎料对变形镁合金AZ31B进行高频感应钎焊。采用扫描电镜、X射线衍射仪、X射线能谱等分析钎焊接头的显微组织及钎缝物相,测试钎焊接头的力学性能及显微硬度。结果表明:在钎焊过程中熔融的Al基钎料与固态的AZ31B母材发生强烈的合金化作用,原始钎料中均一的Mg32(Al,Zn)49相在钎焊后完全消失,同时在钎缝中生成α-Mg、β-Mg17(Al,Zn)12相。钎焊搭接接头的平均抗剪强度达到44MPa,对接接头的平均抗拉强度达到71MPa。接头的断裂形式为沿晶脆性断裂,断裂产生在β-Mg17(Al,Zn)12硬脆相处。     

Modeling of the Prediction of Densification Behavior of Powder Metallurgy Al–Cu–Mg/B_4C Composites Using Artificial Neural Networks

Al–Cu–Mg/B4 Cp metal matrix composites with reinforcement of up to 20 wt% were produced using the powder metallurgy technique. The effects of reinforcement ratio, reinforcement size, milling time, and compact pressure on the density and porosity of the composites reinforced with 0, 5, 10, and 20 wt% B4 C particles were studied. Moreover, an artificial neural network model has been developed for the prediction of the effects of the manufacturing parameters on the density and porosity of powder metallurgy Al–Cu–Mg/B4 Cp composites. This model can be used for predicting the densification behavior of Al–Cu–Mg/B4 Cp composites produced under reinforcement of different sizes and amounts with various milling times and compact pressures. The mean absolute percentage error for the predicted values did not exceed1.6%.     

采用Al及Al-12Si中间层的AZ31B镁合金TLP接头的组织和性能

采用Al及Al-12Si为中间层对AZ31B镁合金进行过渡液相扩散焊,用环境扫描电镜及万能试验机测试并分析了接头组织与强度之间的关系。研究结果表明：采用Al作为中间层时,随着保温时间的增加,Al12Mg17金属间化合物含量降低,接头强度升高;采用Al-12Si作为中间层时,含硅相Mg2Si对焊缝的强化提高了接头强度,但保温时间过长时,Mg2Si偏聚于焊缝中心会降低接头性能。     

带材破碎制备Fe_（78）Si_9B_（13）非晶合金粉末及其磁粉芯性能

对带材破碎法制备Fe78Si9B13非晶合金粉末及其磁粉芯的性能进行了研究。球磨气流复合破碎法是带材破碎制粉的有效途径之一。通过与美国Magnetics相同磁导率磁粉芯产品的磁性能对比,证明Fe78Si9B13非晶磁粉芯是综合性能良好的一种新型磁粉芯。     

Degradation of Methylene Blue and Rhodamine B Using a New Visible Light-Responsive Photocatalyst,KSb2PO8-xNy

Potassium phosphatoantimonates, KSb_2PO_8(KSbPO) and KSb_2PO_(8-x)N_y(KSbPON), are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both KSbPO and KSb PON are characterized by powder X-ray diffraction(PXRD), scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy and UV–visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of KSb PO and KSbPON are refined by least square fitting the PXRD data, using POWD software to obtain their unit cell parameters. The bandgap energy(Eg) of both pristine and N-doped KSbPO is found from their Kubelka–Munk plot. The KSb PON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of OH in the presence of KSb PON during the photoreaction is verified by a fluorescence technique using terephthalic acid(TA) as a probe.     

镁合金与钛合金的瞬间液相扩散焊

为实现镁合金AZ31B与钛合金Ti6A14V的可靠连接，研究了两者以Al为中间层的瞬间液相扩散焊接头的微观结构与连接强度。研究结果表明：当焊接时间为180min时，焊接温度是影响界面反应热力学与动力学的主要参数，其对接头的微观组织、接头界面新生相构成与连接强度有重要影响。保温温度低于450℃时，AZ3IB／AI界面无液相产生，无法实现AZ31B与Ti6A14V的可靠连接；保温温度在450℃～480℃变化时，温度对AZ31B／Al／Ti6A14V界面反应的动力学因素有明显影响，且直接决定了焊后接头新生相的构成与分布。470℃保温180min的接头剪切强度较高（72．4MPa），达到AZ31B母材（86MPa）的84．2％。