Cu在Ni-Mo-P镀层的低温扩散行为

通过化学镀的方法在Cu基底上制备了不同晶态的Ni-Mo-P镀层,对Ni-1.0 at%Mo-17.0 at%合金镀层进行了200~600℃的真空热处理后,利用X射线荧光光谱仪、X射线衍射仪、俄歇电子能谱仪、能量散射谱仪对样品的厚度、成分、物相结构进行了表征与分析。结果表明,随着P含量的增加,合金镀层的晶态由结晶到混晶、非晶转变。随着热处理温度的增加,镀层本身结晶性提高,Cu原子扩散到镀层中,从而影响镀层的晶态。通过计算可得,400和500℃时,Cu扩散量为4.14 at%、6.14 at%。Cu在Ni-1.0 at%Mo-17.0 at%合金镀层中的扩散激活能为1.11 eV。     

Cu互连中Ta-Si-N/Zr阻挡层热稳定性的研究

用射频反应磁控溅射的方法在Si(100)衬底和Cu膜间制备Ta-Si-N(10 nm)/Zr(20 nm)双层结构的扩散阻挡层.Cu/Ta-Si-N/Zr/Si样品在高纯氮气的保护下从600至800℃退火1 h.通过四探针电阻测试仪(FPP)、SEM、XRD和AES研究Cu/Ta-Si-N/Zr/Si系统在退火过程中的热稳定性.结果表明:沉积到Zr膜上的Ta-Si-N表面平坦,为典型的非晶态结构;Cu/Ta-Si-N/Zr/Si样品650℃以上退火后Zr原子扩散到Si中形成的ZrSi2能有效地降低Ta-Si-N与Si之间的接触电阻;Ta-Si-N/Zr阻挡层750℃退火后仍能有效地阻止Cu的扩散.     

W-Ti-N薄膜的制备及其热稳定性

以W-10%Ti二元合金靶材为原材料,采用直流磁控溅射法在Si基体上制备了W-Ti-N三元薄膜,研究了N_2分压和溅射功率对薄膜相结构和N含量的影响;在W-Ti-N/Si结构的基础上制备了Cu/W-Ti-N/Si多层结构,并对其在不同的温度下进行真空热处理。结果表明:通过调整N_2分压和溅射功率,即N_2/Ar比为1∶3且功率为70 W时可以获得非晶态W-Ti-N薄膜。薄膜在700℃以下热处理时具有非常好的热稳定性,方块电阻小于0.6Ω/□,略高于退火前的0.285Ω/□。但退火温度超过700℃后,稳定性迅速下降,在800℃退火后方块电阻达到170Ω/□。Cu布线用W-Ti-N非静态薄膜扩散阻挡层退火过程中的失效机理主要为元素间的界面扩散及反应。     

Fe-Co-Si-B非晶态溅射薄膜的热稳定性

Egami等曾提出Fe_(80)B_(20)溅射合金的T_(Cr)比同成分液淬合金高50K;Tsumashima等则报道Fe基溅射薄膜的T(Cr)比液淬合金略低或相等,Herold等用电镜方法研究了蒸发FeB合     

Ni/Cu比对锆基非晶合金热稳定性与力学性能的影响

采用铜模吸铸法制备了直径为2 mm的Zr_(70)Al_8Cu_(22-x)Ni_x(x=8.5,9,9.5,10,10.5,11)合金,通过差示扫描量热法(DSC)、单轴压缩实验等方法研究了Ni/Cu比对Zr基非晶合金热稳定性与力学性能的影响。结果表明,随Ni/Cu比增加,过冷液相区宽度ΔTx基本在80~81 K之间,但Ni/Cu比为0.63和0.76时对应较高的ΔTx,在Ni/Cu比为0.76时,热稳定性达到最大值89 K,热稳定性较好;随Ni/Cu比增加,塑性应变整体呈下降趋势,但在Ni/Cu比为0.76时出现反常增大,具有良好的塑性,屈服强度整体呈下降趋势,其变化的规律性不强,存在波动性。弹性模量在Ni/Cu比为0.63时达到最大值80 GPa,其余Ni/Cu比合金则在58~65 GPa范围内变化;总体来讲,Ni/Cu比为0.63时的合金塑性应变、屈服强度及弹性模量E均达到最大值。     

形变Cu基原位复合材料热稳定性研究

利用光镜和扫描电观察了形变Ｃｕ－３Ａｇ－１０Ｃｒ原位复合材料退火时Ｃｒ纤维形态的变化。研究发现,Ｃｒ纤维不稳定性表现为四个阶段：纵向分裂,圆柱状化,断开球化和粗化。分析了其机理并测定了断开动力学曲线。     

形变Cu基原位复合材料热稳定性研究

利用光镜和扫描电镜观察了形变Cu 3Ag 10Cr原位复合材料 (η =3 95 )退火时Cr纤维形态的变化 .研究发现 ,Cr纤维不稳定性表现为四个阶段 :纵向分裂、圆柱状化、断开、球化和粗化。分析了其机理并测定了断开动力学曲线。     

酸性Ni-Mo-P/Ni-P双层化学镀工艺研究

对酸性Ni-Mo-P／Ni—P双层直接连续化学镀的工艺进行了试验研究。通过对钼酸根与次磷酸根加量比对镀速的影响，络合剂与pH对镀速及成分影响的研究，优化得到一种双层化学镀的酸性镀液的组成。试验研究了钼含量对镀层结构的影响，进而确定了具有非晶结构的双层镀的最佳工艺并对其性能进行了研究。     

化学镀非晶Ni-P/Ni-Mo-P合金形成机理

通过在镀液中加入Na2 MO4的化学沉积法对酸性Ni Mo P/Ni P双层化学镀的工艺进行了实验研究。通过一系列实验 ,确定了用连续施镀法制备此多元合金镀层的工艺。通过对镀层的成分与结构关系及镀层成分与工艺参数关系的实验研究 ,从热力学角度提出了非晶态双层镀镀层合金膜材的形成机理。     

SiO 2基底上化学镀Ni-Mo-P薄膜的生长和形成机理

采用化学镀方法在SiO2/Si 基底上制备Cu互联线用阻挡层材料Ni-Mo-P薄膜。采用场发射扫描电子显微镜、电子分散能谱仪、原子力显微镜分析不同沉积时间样品的表面形貌和成分,并对Ni-Mo-P薄膜的形成过程进行研究。Ni-Mo-P薄膜的形成过程分为3个阶段：催化阶段,先前还原的Pd颗粒成为Ni还原的催化形核中心,诱导Ni沉积;覆盖阶段,Ni颗粒诱导Mo、P与之进行共沉积;自生长阶段,Ni-Mo-P薄膜共同沉积,颗粒生长。阐述了还原剂被氧化后产物为3-4PO 的的反应机理。     

镍铬铝-硅藻土可磨耗封严涂层的热稳定性

采用等离子弧喷涂工艺制备MCrAlY粘结层、火焰喷涂工艺制备镍铬铝-硅藻土可磨耗封严涂层,在高温氧化气氛条件下进行热稳定试验,研究高温条件下涂层力学性能随时间变化的规律,并进行微观组织分析.试验结果表明,涂层结合强度随热稳定时间的延长而降低,硬度提高,尤其是在热稳定时间5 h时,其性能变化尤为明显;微观组织分析显示,热...     

脉冲电沉积纳米晶Ni-Co-Fe-P合金镀层的热稳定性

用脉冲电沉积方法制备了纳米晶Ni-Co-Fe-P合金镀层.采用X射线衍射(XRD)、透射电镜(TEM)、能谱分析(EDS)、差示扫描量热法(DSC)以及显微硬度计等测试方法研究合金镀层的微观结构、显微硬度和热稳定性.结果表明,纳米晶Ni-40.41%Co-6.16%Fe-1.63%P合金镀层的晶体结构为单一面心立方结构,其平均晶粒尺寸仅为8.8 nm,并具有(111)织构.该镀层的显微硬度随着退火温度的升高而上升,在300和450℃之间达到最大值,之后随退火温度的继续提高而逐步降低.在450℃退火后,晶粒长大到35.1 nm;600℃退火后,晶粒长大到160.8 nm,达亚微米级.在晶粒长大过程中伴有结构的转变,镀层由(111)织构向(200)织构转变.在升温速率为20 K/min的DSC曲线中,该镀层在474.4℃开始放热,并出现明显的放热峰,峰值温度为499.1℃,放热焓为9.086 J/g;通过Kissinger方程式求出该镀层晶粒长大的激活能为369.3 kJ/mol,具有很好的热稳定性.     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

Thermal stability of a Cu/Ta multilayer: an intriguing interfacial reaction

When a Cu/Ta multilayer is formed by sputtering, it is found that the Cu has the equilibrium f.c.c. structure whereas the Ta is in a metastable tetragonal (β-Ta) form. The transformation of the latter into the stable b.c.c. phase (α-Ta), in the presence of Cu, is the subject of the present study. We observed that for a Ta film alone without Cu, the phase transformation starts at about 800°C. In a Cu/β-Ta multilayer, we found from X-ray diffraction analysis that a large amount of β-Ta already transformed into b.c.c.-Ta upon annealing at 700°C, which is much lower than the transformation temperature of Ta by itself. Our transmission electron microscopy (TEM) analysis furthermore reveals that during annealing at around 600°C, small α-Ta grains nucleate at the Cu/β-Ta interface and grow into Cu. Annealing at 800°C results in a complete transformation of the multilayer into the agglomeration of separate Cu and α-Ta grains. Also, we observed that an amorphous layer about 2 nm thick forms upon annealing at 500°C in the Cu/β-Ta system, which has a slightly positive heat of mixing. In energy dispersive spectroscopy (EDS) analysis, the Cu/β-Ta interface of as-deposited samples is found to be chemically discrete, while the Cu/β-Ta interface of a 600°C annealed sample shows extensive interdiffusion and the amorphous layer formed at the interface is found to be a mixed layer of Cu and Ta. Upon annealing at a higher temperature (800°C), no amorphous layer appears and the interface is found to be chemically abrupt. We conclude that the microstructural change of the multilayer is the process of the Ta phase transformation and this occurs through the interaction with Cu. We, furthermore, discuss the amorphization in the Cu–Ta system based on a calculated free energy diagram.     

飞机发动机用AlSi-ployester可磨耗封严涂层的热稳定性

采用等离子弧喷涂技术制备了AlSi-ployester涂层并在不同热处理温度和时间内进行热处理,利用扫描电镜、CMT5605型电子万能实验机、TH320表面硬度仪等研究分析了热处理前后涂层的组织结构、结合强度、硬度等性能.通过对试验结果的归纳、分析,探讨了涂层结合强度和硬度与热处理温度和时间之间的关系.结果表明,随着热处理温度和时间的提高,涂层硬度和结合强度有所降低.当涂层经300℃×300h热处理后结合强度为4.79MPa,硬度为HRC325,满足使用要求.     

Thermal stability of nanostructured NiCrC coating prepared by HVAF spraying of cryomilled powders

Thermal stability of nanostructured NiCrC coating prepared by high velocity air-fuel (HVAF) spraying of cryomilled feedstock powders was investigated.Transmission electron microscopy (TEM),differential scanning calorimetry (DSC),and X-ray diffraction (XRD) were utilized for characteristic analysis.Recrystallization and normal grain growth occur when isothermal treatment is performed at 923 K (0.55 TM) for up to 100 h,and the average grain size increases from initial 41 nm for as-deposited state to around 100 nm for nearly equilibrium state.Isochronal treatment at 823 K and 1023 K was also conducted for comparison.Accordingly,for 0.49 to 0.61 T/TM,the time exponent n deduced from D1/n - D1/0/n = kt increases from 0.15 to 0.30.The observed high thermal stability is attributed primarily to a Zener pinning mechanism arising from the fine Cr2O3 dispersions and the solute drag effect as well.     

Thermal stability of discontinuous precipitation in the Al-Zn-（Cu） system

The coarsening mechanism and kinetics of discontinuous precipitation (DP) in A1-Zn-(Cu) alloys were studied by means of optical microscopy, scanning electron microscopy, and X-ray diffraction analysis. The results show that the coarsening mechanism is different as the aging temperature varies. At a low temperature (150℃), the coarsening occurs through the dissolution and spheroidization of fme laminar structure of DP; at high temperatures (above 200℃), the discontinuous coarsening (DC) of DP microstructure mainly occurs, forming coarsening cells with a larger laminar distance. The growth velocity of coarsening cells rapidly reaches the maximum, and then decreases with the increase of time. The coarsening velocity of DP microstructure decreases due to the addition of Cu element.     

Thermodynamic stability of Co/Cu multilayered nanostructures

In this paper, the Regular Solution Model (RSM) and the Cluster/Site Approximation (CSA) were used to study the unmixing as a function of the thickness of the Co/Cu metal layers. The results show that decreases in the thickness of the layers leads to a lowering of the demixing critical temperature.     

Thermal shock testing of thermal barrier coating/bondcoat systems

Various methods of thermal shock testing are used by aircraft and industrial gas turbine engine (IGT) manufacturers to characterize new thermal barrier coating systems in the development stage as well as for quality control. The cyclic furnace oxidation test (FCT), widely used in aircraft applications, stresses the ceramic/bondcoat interface, predominantly through thermally grown oxide (TGO) growth stress. The jet engine thermal shock (JETS) test, derived from a burner rig test, creates a large thermal gradient across the thermal barrier coating (TBC), as well as thermomechanical stress at the interface. For IGT applications with long high-temperature exposure times, a combination of isothermal preoxidation and thermal shock testing in a fluidized bed reactor may better represent the actual engine conditions while both types of stress are present. A comparative evaluation of FCT, JETS, and a combined isothermal oxidation and fluidized bed thermal shock test has been conducted for selected ceramic/bondcoat systems. The results and the failure mechanisms as they relate to the TBC system are discussed. A recommendation on the test method of choice providing best discrimination between the thermal shock resistance of the ceramic layer, the ceramic/bondcoat interface, and even substrate related effects, is given. This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September 15–17, 2003, in Indianapolis, Indiana, and appeared on pp. 520–29.     

Laser cladding of Ni/Cu/Al functionally graded coating on magnesium substrate

Laser cladding of graded multi-layer Ni/Cu/Al coatings on magnesium substrates was performed with the aim of improving the inherently low corrosion and wear resistance of magnesium. The quality of the coating was found to be good: the interfaces between the different layers are generally free from any major solidification defects such as porosity and cracks. Despite the fact that considerable mixing had occurred in the Al layer, the top Ni layer was free from Al and Mg. The top Ni layer comprises a single solid solution (Ni) phase; its corrosion and wear resistance was found to be excellent. The wear properties of the coating were explained in terms of stacking fault energy and the ratio of hardness to elastic modulus.