含微量镁的Ni-Co-Cr-W-Mo-Al-Ti变形高温合金晶界的显微结构

在Ni-15Co-10Cr-5.5W-5.5Mo-4Al-2.5Ti变形高温合金中加入微量镁,能明显改善合金的中温和高温性能。但对镁的含量非常敏感;在此合金中,最佳镁含量为0.007wt％。只有在达到最佳值时,性能才能明显改善,稍过量,即可明显变坏。本工作以高空间分辨率分析电子显微术及晶格象作手段,对几种不同镁含量的此合金中     

激光立体成形Ti-Al-V系的合金力学性能

研究了以元素粉末为送进原料时,激光立体成形(LSF)Ti-Al-V系合金的力学性能。结合激光立体成形Ti-xAl-yV(x≤10,y≤25)合金的硬度测试分析和人工神经网络模型优化,获得激光立体成形Ti-xAl-yV合金成分-硬度的关系。选择典型成分合金进行室温拉伸性能测试,在此基础上获得激光立体成形钛合金抗拉强度与显微硬度的比例因子K值为2.86～3.00,可实现对激光立体成形Ti-xAl-yV(x≤10,y≤25)合金的抗拉强度预测。另外,室温拉伸性能测试结果表明,激光立体成形Ti-4Al-3V、Ti-5Al-3V、Ti-4Al-4V、Ti-5Al-4V以及Ti-3Al-6V沉积态的综合室温拉伸性能均达到Ti-6Al-4V合金的锻件标准。     

(Er-Zr)对SLM制备车用Al-12Si合金组织演变及性能强化的影响

为了提高SLM成形Al-12Si合金的综合性能，通过气雾处理方式加入Er、Zr元素后进行SLM制备Al-12Si-(Er-Zr)合金。通过试验测试手段研究其微观结构、物理力学特性等指标，深入分析Er与Zr元素在Al-12Si-(Er-Zr)合金SLM加工过程中的强化作用机制。研究结果表明：在能量密度达到57.5 J/mm³时，合金获得99.2%的最高相对密度。SLM制备Al-12Si-(Er-Zr)合金中存在灰色Al与白色共晶Si组织，呈网状分布形态特征，Er、Zr元素可以对Al-12Si-(Er-Zr)合金起到明显晶粒细化的效果。与Al-12Si合金相比，SLM制备Al-12Si-(Er-Zr)合金硬度增大了26.1%,合金拉伸强度增大20%,屈服强度增大27%,伸长率变化不明显。SLM制备Al-12Si-(Er-Zr)合金晶粒都达到较大的Schmid因子，含有更多的高Taylor因子，更高比例Brass冷轧织构和Copper拉伸织构，使Al-12Si-(Er-Zr)合金获得更高的力学强度。     

离子减薄诱发的Zr65Al7.5Ni10Cu17.5块状非晶晶化相的相变

用透射电子显微镜研究了锆基块状非晶合金晶化行为，对分别经双喷电解减薄加离子减薄和单纯双喷电解减薄制备的电镜样品进行观察分析，发现离子减薄会导致该合金晶化亚稳相的转变。     

在长期室温时效中NiAl3和Ni2Al3合金相成分与结构的变化

NiAl3和Ni2Al3是Ni-50wt．％Al二元合金中的两个主要合金相。已经观察到在离子减薄过程中这两个合金相的化学成分会发生变化。本文对放置4年后的Ni-50wt．％Al合金进行了TEM／EDS和HREM研究，观察到在室温时效后两个合金相成分和结构的变化。     

固溶处理后镁铝合金时效峰值硬度时微观结构的电子显微分析

用显微维氏硬度计、金相显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究分析了Mg-10.33wt.%Al-1.26wt.%Zn合金固溶后的时效硬化规律。实验结果表明AZ91(Mg-9wt.%Al-1wt.%Zn-0.2wt.%Mn)合金添加少量的Al后固溶强化和时效强化效果均有显著提高。实验的时效硬度曲线表明:固溶处理后的Mg-10.33wt.%Al-1.26wt.%Zn合金在473K时效10 h获得最佳时效强化效果。经过分析,进一步证实Mg-10.33wt.%Al-1.26wt.%Zn合金固溶后时效过程中单位体积内的连续析出相γ-Mg17Al12相颗粒的数目(Nv)越大,样品的显微硬度值越高。     

氧化物半导体透明导电薄膜的最佳掺杂含量理论计算

以铝掺杂氧化锌 (Al- doped Zn O,简称 AZO)和锡掺杂氧化铟 (Sn- doped In2 O3,简称 ITO)薄膜为例 ,建立了一个氧化物半导体透明导电薄膜的最佳掺杂含量的理论表达式 ,定量计算的结果 AZO陶瓷靶材中铝含量的理论最佳值为 C≈ 2 .9894% (wt) ,ITO陶瓷靶材中锡含量的理论最佳值为 C≈ 10 .3114% (wt) ,与实验数据相符合 .该理论经适当的修改和解释后也适用于某些其他电子薄膜材料的最佳掺杂含量问题     

INCONEL718合金中相转变的电镜观察

INCONEL718(简称IN718)合金是以DO_(22)结构的γ″-Ni_3Nb为主要强化相并含有一定量的γ′-Ni_3Al相起辅助强化作用的铁镍基高温合金。亚稳相γ″对应的稳定相为具有DOa结构的δ-Ni_3Nb。本文利用经过数万小时长期运行的IN718部件(具有连续分布的温度梯度,预测最高温度到650℃)进行详细的TEM观察。     

Al-Mg-Si-Cu合金中晶界和晶内析出相粗化规律的研究

采用显微硬度测试仪、扫描电镜和透射电镜观察及能谱分析,研究了Al-0.5Mg-1.0Si-0.8Cu(wt.%)合金的晶界析出规律和晶内析出相的粗化机制。结果表明:180℃时效处理的Al-0.5Mg-1.0Si-0.8Cu(wt.%)合金晶界处存在富Si相和Q相两类不连续分布的析出相,它们的尺寸分别约为1 mm和几十纳米;时效0.5 h时晶界处有少量富Si相,时效5 h时晶界富Si相明显增多,时效36 h时富Si相开始粗化且间距变大,再进一步时效其形貌和分布变化不大;晶界Q相与相邻晶粒铝基体的界面取向关系是:[510]Al//[1120]Q;时效36 h晶内开始出现粗化析出相,且随时效继续进行合金晶内析出大量粗化相,存在明显的晶界无析出带现象。晶内粗化析出相主要含有Si元素,呈片状、球状和棒状3种形貌。其中,棒状Si析出相是沿〈001〉Al方向生长的,且〈112〉Si//〈001〉Al,{111}Si//{010}Al。     

新型绿色节能技术在活塞工业中的应用——电磁脉冲技术在Al-25%Si-1.7%Mg合金中的应用

将电磁脉冲技术应用在Al-25%Si-1.7%Mg合金(新型活塞材料)的热处理过程中,一方面能够降低Al-25%Si-1.7%Mg合金热处理过程中的能耗,从而降低生产成本,减少废气排放;另一方面,电磁脉冲技术可优化Al-25%Si-1.7%Mg合金的组织,提高其力学性能,使其在工业中得到更广泛的使用。     

Smooth indium zinc oxide film prepared by sputtering a In2O3:ZnO=95:5 target

Indium zinc oxide (IZO) films with surface roughness Ra<0.3 nm have been prepared by radio frequency sputtering. The IZO film is the possible candidate for replacing the indium tin oxide (ITO) film in pattern precision or low processing temperature concern. Instead of commonly used In₂O₃:ZnO=90:10 in weight percentage (wt%) target, a target doped with 5 wt% impurities was used in this study. It was found that the electrical resistivity of the IZO film increases rapidly if oxygen gas was introduced during the sputtering process. This increase tendency in electrical resistivity is much more significant than the IZO film prepared with a 10 wt% doped ZnO target. The electrical resistivity increased rapidly as soon as the IZO film became crystallized in heat treatment. Optical properties of the IZO film do not change significantly with varying process parameters. The appropriate processing condition for the prepared IZO film is no oxygen feeding and no heat treatment.     

Effect of Mg doping on increase in the life with low contactresistance of Ag-Pd alloy switching contacts in silicone vaporenvironments

When silicone vapor adsorbed on contact surfaces is subjected to high temperature due to electric discharge in the atmosphere, SiO₂ is formed by chemical decomposition of the adsorbed silicone molecular. When SiO₂ is formed on contact surfaces and is caught in the interface of contacts, contact failure is caused by an insulation property of SiO₂. Newly developed contact material of Ag(40wt%)-Pd(60wt%) alloy with a small amount of dopant of Mg was applied experimentally to a microrelay. This material shows remarkable improvement of contact resistance property for contaminant oxide film in comparison with usual Ag-Pd contacts. In this study, the contact resistance property for the number of make-break switching operations of the Ag-Pd-Mg alloy was examined by wide range electrical conditions under saturated (1300 ppm) silicone vapor. Obtained contact resistance properties were compared with the Ag-Pd alloy itself and Ag-Pd overlaid with Au(90wt%)-Ag(10wt%) which is usually used. As a result, prolonged low contact resistance property of the Ag-Pd-Mg alloy for silicone environment was found. The mechanism of the low contact resistance property was clarified by cleaning effect based on removal of powder products formed from the contact traces. Moreover, activation of contact surfaces due to formation of MgO (magnesium oxide) on the surface of the Ag-Pd-Mg alloy was not observed by examination of arc duration. The arc duration of the Ag-Pd-Mg alloy was not as long as usual Ag-Pd alloy contact     

底镀层对陶瓷封装芯腔表面高温变色的影响

研究了Ni底镀层和不同Co含量的Ni-Co合金底镀层对陶瓷封装芯腔镀金层表面抗高温变色能力的影响。420℃、15 min的高温考核表明:w(Co)超过10%以上的Ni-Co合金底镀层,对陶瓷封装芯腔表面抗高温变色能力明显优于纯Ni底镀层。镀层中w(Co)超过10%以上时,抗高温变色能力并不会随着Co含量增加而提高,仅随底镀层厚度的增加而明显增强。因而在陶瓷封装中,采用厚度大于4 mm的、含Co 15%左右的Ni-Co合金,代替Ni作为底镀层是可行的。     

Effects of sulfur addition on the wettability and corrosion resistance of Sn-0.7Cu lead-free solder

The effects of sulfur on the wettability of Sn-0.7Cu on Cu and on the corrosion behavior of Sn-0.7Cu in 3.5 wt% NaCl solution were investigated. The results reveal that sulfur considerably improves the wettability of Sn-0.7Cu and the optimal sulfur content is 0.08 wt%. SnS and SnSO₄ phases form on the surface of the sulfur containing Sn-0.7Cu solder alloy after soldering characterized by XPS and XRD analysis. The addition of sulfur decreases the dross formation of the solder melt and the formation of SnO₂ is inhibited. The potentiodynamic polarization tests show that the corrosion resistance of Sn-0.7Cu solder alloy is obviously enhanced by sulfur element. Analyses by SEM and XRD indicate that sulfur promotes the formation of the corrosion product, Sn₃O(OH)₂Cl₂, on the surface of sulfur containing Sn-0.7Cu solder and it keeps the solder alloy from further corrosion.     

时效处理快速凝固Mg-5 wt.％Sn合金微观结构的电子显微分析

用显微维氏硬度仪、X射线衍射仪（ XRD）、扫描电子显微镜（ SEM）和透射电子显微镜（ TEM）研究分析了快速凝固Mg?5 wt?％Sn合金条带的时效硬化规律。实验结果表明,快速凝固Mg?5 wt?％Sn合金在593 K温度下时效3 h后达到峰值硬度。时效后峰值硬度下的快速凝固Mg?5 wt?％Sn合金中有β?Mg2 Sn相颗粒析出,大多数的析出相β?Mg2 Sn颗粒分布在晶界,少部分析出相β?Mg2 Sn颗粒分布在晶粒内部。在593 K温度下时效3 h后的合金中观察到析出相β?Mg2Sn 颗粒与基体α?Mg 的一种新取向关系：（202261）β／／（0110）α,（7236）β／／（0001）α,[512]β／／[2110]α。     

Microstructural effect on the creep strength of a Sn-3.5%Ag solder alloy

The effect of microstructure obtained by rapid or slow solidification and cooling of a Sn-3.5%Ag lead-free solder alloy on the creep strength has been investigated. The rapidly cooled alloy showed that the microstructure consisted of the primarily crystallized Sn phase and the quasi-eutectic phase, where fine Ag₃Sn particles dispersed in the Sn matrix. In the slowly cooled alloy, large platelets of Ag₃Sn were formed sparsely in the Sn matrix. A difference of about 2.5 orders of magnitude in the cooling rate translates to about 1.5 orders of magnitude in the creep-rupture time. Accordingly, fine particle dispersion of Ag₃Sn is considered to be very beneficial for the restraining of creep deformation, that is, for the decreasing of creep rate of the Sn-3.5%Ag alloy, compared with the effect of large platelets of Ag₃Sn sparsely formed in the Sn matrix.     

基于LIBS 技术铝合金中铁元素的定量分析

为了精确得到铝合金标样等离子体的电子温度和电子密度,实验采用激光诱导击穿光谱技术,利用532 nm 调Q Nd:YAG 激光器诱导产生铝合金E311 等离子体。测量铁原子谱线(381.59 nm)的Stark 展宽(0.12 nm)得到等离子体的电子密度是4.31016 cm-3;基于铁原子谱线(370.56, 386.55,387.25, 426.05, 427.18, 430.79, 432.57, 440.48 nm),利用迭代Boltzmann 算法,得到回归系数为0.999时等离子体的电子温度是8 699 K。基于铝合金标样(E311、E312、E313、E314、E315、E316)和铁原子谱线404.58 nm,建立了铁元素的标准曲线,计算得到铁元素的探测限是0.0779 wt%。等离子体特征参数表明铝合金等离子体满足光学薄和局部热力学平衡状态。     

Microstructural and tensile properties of Fe and Bi added Sn-1Ag-0.5Cu solder alloy under high temperature environment

In this work, the iron (Fe) and bismuth (Bi) added (0.05 wt% Fe and 1 wt% or 2 wt% Bi) Sn-1Ag-0.5Cu (SAC105) lead-free solder alloys were prepared and their microstructure and tensile properties under severe thermal environments were extensively investigated and compared with the base alloy SAC105. The isothermal aging was done at 200 °C for 100 h, 200 h, and 300 h. Fe/Bi added SAC105 showed a significant reduction in the IMCs size (Ag₃Sn and Cu₆Sn₅), especially the Cu₆Sn₅ IMCs and a refinement in the microstructure, which is due to the existence of Bi in the alloys. Moreover, the existence of Fe and Bi gives the microstructure better stability under severe thermal aging conditions. The tensile testing results showed that the addition of Fe and Bi to SAC105 greatly improves yield stress and tensile strength, but decreases ductility level, which is because of the Bi solid solution strengthening mechanism. Under severe thermal aging, the Fe/Bi added SAC105 showed more stable tensile properties, because of the existence of both Fe and Bi in the alloys.     

BT20钛合金的激光表面重熔

激光表面重熔对提高钛合金表面的耐蚀性具有显著的效果.采用脉冲Nd-YAG激光器对BT20钛合金进行了重熔.表面显微结构、硬度分布和在3wt% NaCl与1M HCl溶液中的耐蚀性进行了研究.激光重熔处理后耐蚀性得到显著的提高.耐蚀性的提高归因于快速凝固造成的组织变化.     

TC4激光熔覆Gd元素YSZ热障涂层微观特性研究

通过在钛合金表面引入稀土氧化物改性"7YSZ"即7 wt％氧化钇稳定的氧化锆涂层,提升传统热障涂层的综合性能.采用预制法并应用YLS-3000型光纤激光系统利用激光熔覆技术在TC4钛合金表面制备了不同Gd2 O3添加量的Gd-YSZ涂层,通过光学显微镜、扫描电镜及能谱仪、X射线衍射仪和硬度仪分别表征涂层的宏观形貌、显微...