Cu—Ti合金时效早期相变规律的研究

本文应用透射电子显微镜，Ｘ射线衍射等手段研究了Ｃｕ－Ｔｉ合金时效相变早期的分解过程。研究了表明，过饱和的Ｃｕ－Ｔｉ合金固溶体可能首先发生的是溶质原子的短程有序化，然后通过调发解机理分解为贫富溶质区，富溶质区原子进行长程有序排列，形成了Ｄ１ａ型的ＣｕＴｉ有序相。     

时效处理NiTi合金的相变研究

Ni-Ti形状记忆合金由于其独特的形状记忆效应和超弹性,它的马氏体相变在过去几十年来一直受到巨大的关注。Ti-Ni形状记忆合金有三个不同的相：立方CsCl结构的B2母相,单斜B19’马氏体相和预马氏体R相。在这些相中,可能发生三个相变：B2-B19’、B2-R和R-B19’。R相变可以通过多种方式诱发,例如添加第三组元（Fe、Al）、冷加工、冷加工后不完全退火、热循环和时效处理。     

低碳钢表面激光相变硬化研究

为了研究不同激光功率及不同的冷却条件下,激光相变硬化处理对低碳钢表面性能和组织的影响,采用激光表面相变硬化方法,在低碳钢表面获得了比原先母材硬度高100HV～150HV的硬化层,采用金相显微镜分析了激光处理区的组织,且用显微硬度计测量了单道扫描时的纵向和横向的硬度分布.研究发现,激光作用区主要是低碳板条马氏体与未转变的索氏体甚至屈氏体、回火索氏体组织.搭接区组织均为细小的马氏体及中间分布着索氏体组织;由于10CrNiMo钢含碳量较低和碳扩散系数不同的原因,其最高硬度层并未在表面形成,而是形成在次表层.在软化区,前一道扫描形成的马氏体受到回火作用,原先固溶在马氏体中的碳析出,形成了回火索氏体,降低了硬度.结果表明,激光相变硬化工艺可以将10CrNiMo钢的表面硬度提高100HV～150HV左右,且表面保持很好的韧性,若想进一步提高其表面硬度,还需采取熔覆等其它工艺.     

Cu—Ni—Be高导电耐磨合金时效析出的TEM研究

本文用TEM确定了Cu—Ni—Be合金时效时G·P区和γ’析出相(NiBe)是合金硬度、电导率变化的重要原因,同时确立了NiBe与母相之间的相位关系:(110)_P//(100)_M,[001]_P//[001]_M;惯析面为[001]。     

ZnAl40合金时效过程中组织结构变化的跟踪观察

本文利用扫描电子显微术（SEM），透射电子显微术（TEM）及X射线衍射（XRD）研究了ZnAl40合金在固溶时效过程中的组织结构变化，结果表明，在时效过程中，过饱和固溶体将发生不连续沉淀反应及调幅（Spinodal)分解，不连续沉淀机制形成的胞状（Cellular)组织α η－Zn通过晶界迁移长入已发生Spinodal分解的基体，环境温度下时效，调幅组织将逐渐粗化，形成较细的的粒状亚稳R组织，且调幅分解区与胞状分解区交界处更易粗化。由于析出η－Zn相，过饱和固溶体的点阵参数将增加。     

自然时效和Cu含量对AlMgSi（Cu）合金时效硬化行为的影响

利用硬度测试和透射电子显微镜观察,对Cu含量分别为0.0%、0.15%、0.8%（wt.%）的AlMgSi合金进行了较系统地显微组织结构和时效硬化行为研究。热处理状态为固溶淬火后直接180℃人工时效及固溶淬火后自然时效两周再180℃人工时效。结果表明：添加Cu可以抑制自然时效对180℃人工时效硬度峰值的负面作用;与固溶淬火后先自然时效两周再180℃人工时效峰值样品比较,固溶淬火后直接180℃人工时效峰值样品中针状析出相的数量密度较大;含0.15%Cu的合金峰值时效样品中只观察到β″析出相,而含0.8%Cu的合金峰值时效样品中观察到β″和Q″析出相;与不含Cu和含0.15%Cu的合金比较,含0.8%Cu的合金时效峰值出现时间延迟。这种现象与Q″相的析出有关,因为析出Q″相需要额外的时效时间。     

Ni2FeGa Heusler合金的微结构与低温相变研究

具有体心有序结构的Ni2FeGa合金作为铁磁记忆材料在近期研究中得到了广泛关注。电子显微镜观察分析表明，在急冷条件下制成的带状材料有着丰富的微结构，如图1所示。在低温下，晶体发生马氏体相变，原位电子衍射观察直接显示出由立方结构向单斜结构的转变过程，并且有7倍或者5倍的超结的出现。     

激光相变硬化性能与工艺参数关系的数学模型

用回归正文分析的方法．建立了中碳结构钢、碳素工具钢和合金结构钢的激光相变硬化性能与工艺参数间关系的数学模型。分析了回归力程的显著性并预测了各硬化指标的精度。     

Y-PSZ陶瓷高温扩散相变后显微组织的HREM研究

Ｙ２Ｏ３部分稳定ＺｒＯ２陶瓷（Ｙ－ＰＳＺ）中高温相变是指从立方相（ｃ相）到四方相（ｔ相）的转变。关于这一相变的机理，周玉等［１］及Ｋ．Ｊ．ＭｃＣｌｅｌａｎ等［２］基于电子衍射谱中出现面心立方结构的消光斑点的结果，认为是位于面心立方晶胞中八个间隙位置的...     

铜(钛)和铜(铬)自形成阻挡层性能表征

采用直流磁控溅射法分别将Cu (Ti)和Cu (Cr)合金层沉积在SiO2/Si衬底上,随后将制得的样品在真空(2×10-3 Pa)中退火1h,退火温度为300 ～ 700℃.对Cu (Ti)及Cu (Cr)自形成阻挡层进行对比研究,通过X射线衍射(XRD)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)观察并表征样品的微观结构.通过半导体分析仪测试样品的电学性能,并分析了其热稳定性.结果表明,在Cu膜中分别加入少量的Ti或Cr可使Cu沿〈111〉晶向择优取向生长.两种样品交界面处的Cu及Si元素含量迅速下降,表明在交界面处自形成阻挡层,抑制了Cu与Si元素之间的扩散.Cu (Ti) /SiO2/Si和Cu (Cr) /SiO2/Si样品漏电流测试结果表明,Cr自形成的阻挡层具有更好的热稳定性.     

Formation of Ti diffusion barrier layers in Thin Cu(Ti) alloy films

In order to study a formation mechanism of thin Ti-rich layers formed on the surfaces of Cu(Ti) wires after annealing at elevated temperatures, the 300-nm-thick Cu(Ti) alloy films with Ti concentration of 1.3 at.% or 2.9 at.% were prepared on the SiO₂/Si substrates by a co-sputter deposition technique. The electrical resistivity and microstructural analysis of these alloy films were carried out before and after annealing at 400°C. The Ti-rich layers with thickness of ∼15 nm were observed to form uniformly both at the film surface and the substrate interfaces in the Cu(2.9at.%Ti) films after annealing (which we call the self-formation of the layers) using Rutherford backscattering spectrometry (RBS) and transmission electron microscopy (TEM). Both the resistivities and the microstructures of these Cu(Ti) films were found to depend strongly on the Ti concentrations. The resistivities of the films decreased upon annealing due to segregation of the supersaturated Ti solutes in the alloy films to both the top and bottom of the films. These Ti layers had excellent thermal stability and would be applicable to the self-formed diffusion barrier in Cu interconnects of highly integrated devices. The selection rules of the alloy elements for the barrier self-formation were proposed based on the present results.     

Effects of Substrate Materials on Self-Formation of Ti-Rich Interface Layers in Cu(Ti) Alloy Films

In our previous studies, thin Ti-rich layers were found to uniformly cover SiO₂/Si substrate surfaces at the interface with Cu(Ti) alloy films after annealing at elevated temperature. These Ti-rich layers were also found to prevent intermixing between the Cu(Ti) alloy films and the substrate, resulting in a simple barrier formation technique, called “self-formation of the diffusion barrier,” which is attractive for fabrication of ultra-large scale integrated (ULSI) interconnect structures. In the present study, to understand the mechanism of self-formation of the Ti-rich barrier layers on the substrate surface, the effects of SiO₂/Si, SiN/SiO₂/Si and NaCl substrate materials on the interfacial microstructure were investigated. The microstructures were analyzed by transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS), and correlated with the electrical properties of the Cu(Ti) interconnects. It was concluded that the chemical reaction of Ti with the substrate materials was essential for the self-formation of the Ti-rich layers.     

Cu-Al-Ni合金的马氏体和界面

从１１７３Ｋ淬火的Ｃｕ－１１．２Ａｌ－２．９Ｎｉ合金试样中共存有两类马氏体，一种为Ｍ２Ｈ结构、点阵常数为：ａ＝０．４４６ｎｍ、ｂ＝０．５４０ｎｍ、ｃ＝０．４２４ｎｍ，β＝９２°，由微孪晶组成，另一种为Ｎ９Ｒ结构、含有高密度的层错。研究表明：一片层错型Ｎ９Ｒ马氏体实际上是由许多小的、具有Ｎ９Ｒ或ＦＣＣ或２Ｈ结构的极薄片堆垛起来的混合物。而且９Ｒ型和２Ｈ型两类马氏体在结构上有十分密切的内在联系。本文用电子显微镜等技术研究了这两类马氏体的细结构以及有关界面的特征、稳定性和电子束辐照的影响     

Ti对Sn0.7Cu无铅钎料润湿性和界面的影响

研究了Ti的加入对Sn0.7Cu无铅钎料润湿性能以及钎料/Cu界面微观组织的影响.结果表明:在Sn0.7Cu中添加微量Ti,提高了钎料的润湿性能,可使铺展面积提高5％左右,当钎焊时间为3s时,界面金属间化合物(IMC)形貌由原来的扇贝状变为锯齿状;随着钎焊时间延长,Sn0.7Cu/Cu和Sn0.7Cu0.008Ti/C...     

Characterization of Self-Formed Ti-Rich Interface Layers in Cu(Ti)/Low-k Samples

In our previous studies, thin Ti-rich diffusion barrier layers were found to be formed at the interface between Cu(Ti) films and SiO₂/Si substrates after annealing at elevated temperatures. This technique was called self-formation of the diffusion barrier, and is attractive for fabrication of ultralarge-scale integrated (ULSI) interconnects. In the present study, we investigated the applicability of this technique to Cu(Ti) alloy films which were deposited on low dielectric constant (low-k) materials (SiO _x C _y ), SiCO, and SiCN dielectric layers, which are potential dielectric layers for future ULSI Si devices. The microstructures were analyzed by transmission electron microscopy (TEM) and secondary-ion mass spectrometry (SIMS), and correlated with the electrical properties of the Cu(Ti) films. It was concluded that the Ti-rich interface layers were formed in all the Cu(Ti)/dielectric-layer samples. The primary factor to control the composition of the self-formed Ti-rich interface layers was the C concentration in the dielectric layers rather than the enthalpy of formation of the Ti compounds (TiC, TiSi, and TiN). Crystalline TiC was formed on the dielectric layers with a C concentration higher than 17 at.%.     

Ti/Ag/Cu活性焊料的封接特性

Ti／Ag／Cu活性焊料法广泛应用于陶瓷与金属的焊接中，但该焊料在陶瓷表面的浸润性较差，在金属表面易发生偏析的现象。本文对该焊料的流散特性进行了讨论，对陶瓷与金属的封接界面进行了分析，对封接机理进行了讨论，结果表明在封接界面生成Ti的氧化物主要是TiO2。     

TiNi合金相变的原位观察

本文利用透射电镜原位观察研究ＴｉＮｉ合金中的相变。研究表明，ＴｉＮｉ合金中电子衍射谱上的漫散射条纹的出现是由于具有＜１１１＞极化的声子模软化，经张应有利于Ｒ相及马氏体相形核有关的软模。     

时效对Sn3.0Cu0.15Ni/Cu界面组织的影响

研究了150℃时效0,200,500h对Sn3.0Cu0.15Ni/Cu界面组织结构的影响.结果表明:界面金属间化合物层由Cu6Sn5层和Cu3Sn层组成,质量分数为0.15％的Ni的加入会使IMC层最初变厚,但在时效过程中,热稳定性强的界面化合物(Cu,Ni)6Sn5的生成,会抑制Cu3Sn化合物层的生长;同时Ni的加入会降低Cu6Sn5颗粒的长大速度,并且随着时效时间的延长,Cu6Sn5颗粒的形貌呈多面体结构.     

Rutherford Backscattering Spectrometry Analysis of Self-Formed Ti-Rich Interface Layer Growth in Cu(Ti)/Low-<Emphasis Type="Italic">k</Emphasis> Samples

A new fabrication technique to prepare ultrathin barrier layers for nanoscale Cu wires was proposed in our previous studies. Ti-rich layers formed at Cu(Ti)/dielectric layer interfaces consisted of crystalline TiC or TiSi and amorphous Ti oxides. The primary control factor for the Ti-rich interface layer composition was C concentration in the dielectric layers rather than the formation enthalpy of the Ti compounds. To investigate Ti-rich interface layer growth in Cu(Ti)/dielectric layer samples annealed in ultrahigh vacuum, Rutherford backscattering spectrometry (RBS) was employed in the present study. Ti peaks were obtained only at the interfaces for all samples. Molar amounts of Ti atoms segregated to the interfaces (n) were estimated from Ti peak areas. Log n values were proportional to log t values. Slopes were similar for all samples, suggesting similar growth mechanisms. The activation energy (E) for Ti atoms reacting with the dielectric layers containing carbon (except SiO₂) tended to decrease with decreasing C concentration (decreasing k), while those for the SiO₂ layers were much higher. Reaction rate coefficients [Z · exp(−E/RT)] were insensitive to C concentration in the dielectric layers. These factors lead to the conclusion that growth of the Ti-rich interface layers is controlled by chemical reactions, represented by the Z and E values, of the Ti atoms with the dielectric layers, although there are a few diffusion processes possible.