多晶铍微观弹性失配行为的数值分析

考虑了晶粒取向随机的影响,分别建立了多晶铍的规则和非规则晶形二维多晶模型,对多晶铍的微观弹性失配行为进行了有限元(FEM)数值分析。规则模型晶粒形状取为正方形或正六边形;非规则模型利用Voronoi方法获得接近真实的非规则形状晶粒。考虑到单晶体力学性能的各向异性,对具有HCP结构单晶铍晶粒的含有5个参数的弹性刚度矩阵进行坐标变换,得到任意取向铍晶粒的弹性性能参数。将各组弹性性能参数随机地赋给各个晶粒,实现在晶粒取向随机化分布条件下对弹性性能差异性考虑的目的。基于以上工作对两类铍多晶模型进行了FEM应力分析,结果表明,两类不同模型的失配应力集中均发生在晶界处;相比规则多晶模型,不规则多晶模型的弹性失配效应更为显著;最大失配应力较平均应力(即不考虑弹性失配影响时的应力)高出10%左右。     

二维原子晶体材料中表层氧缺陷的调控及物性研究获进展

<正>二氧化铈(CeO_2)是一种可还原氧化物材料,它可以在还原性气氛中产生表层氧缺陷,在氧化性气氛中修复氧缺陷。这种氧离子存储特性使得它在燃料电池固态电解液材料、高性能汽车尾气净化器等方面有非常好的应用前景。CeO_2(111)二维原子晶体材料(或薄膜)最表层的O-Ce-O单元层里存在着表层和亚表层两种氧缺陷,但在     

45号钢中镁铝尖晶石夹杂物诱导晶内铁素体析出形成机理研究

以热力学基本原理和错配度理论为基础,计算分析45号钢内镁铝尖晶石的形成过程,在45号钢的液相线温度下,钢液中的氧活度一定的情况下,氧化铝会优于氧化镁生成,并且计算了铝元素一定的情况下,只要有微量的镁就可以生成镁铝尖晶石夹杂物。并通过二维错配度的计算证明了镁铝尖晶石和晶内铁素体的匹配关系良好,容易形成共格结构,为晶内铁素体的析出提供了良好的基底面。     

小方坯碳偏析模拟研究

基于Fluent建立了150 mm×150 mm结晶器的三维模型，模拟计算了结晶器内流场、温度场及溶质分布的变化，并对二冷区宏观偏析进行了模拟.结果发现，结晶器角部传热方式为二维传热，与表面一维传热相比凝固速度较快.结晶器角部钢液存在回流，同时弯月面处钢液也存在小的回流.受回流及凝固的影响，碳元素在结晶器内会重新分配，上部表现为正偏析、回流通道表现为负偏析.并且发现，由于固液相扩散系数的不同，直到凝固终点，铸坯冷却过程中都会存在环形负偏析.      

不同不锈钢板偏析的原位统计分布技术解析

采用金属原位统计分布分析技术,结合传统分析手段,综合解析了系列不同不锈钢板横截面各元素的偏析分布规律和样品疏松程度。采用含量二维等高图、含量三维视图等观察了各元素的偏析分布状态,利用最大偏析度以及统计偏析度等对各元素的偏析程度进行了定量表征。结果表明,每个不锈钢板样品中均有某些元素表现出明显的、特定的偏析分布规律,如有些样品C元素在板中心两侧形成两条正偏析带;有些样品Nb元素在板中心形成负偏析;有的样品S元素在板中心线则形成正偏析等,每个样品元素的偏析分布规律可合理解释其低倍的疏松表现形式。此外,各样品S     

原料携带水对铝液中氢形成影响机制研究

采用分子动力学方法模拟研究H_2O与铝反应势垒及其反应物去向,结果表明:原料携带H_2O跟铝反应分解成H~+和OH~-,产生的OH~-跟表面铝原子作用形成Al-O-H化合物,产生的H~+离子与表面铝原子的距离不断减小(0.267,0.211,0.159 nm),并稳定存在于铝表面。熔体中的H是以原子或离子形式进行扩散,在纯铝熔体中不会形成H_2分子,界面处单个H原子以比较稳定的形式存在,多个H原子在气液界面处极易形成H_2。氢原子处于铝晶胞八面体间隙位置时最稳定。H扩散路径是从铝八面体间隙位置到四面体间隙位置再到八面体间隙位置。依据模拟试验结论,以电解铝液为原料,配制了一组Al-Zn-Mg-Cu-0.04Ti-0.18Zr合金,采用扫描电镜研究了铸样凝固组织,结果表明:电解铝液中氢对合金铸样组织产生冶金遗传影响,铸态合金试样中存在大量的气孔和气泡,氧化夹杂周围气孔比较发达,表明气体和氧化铝夹杂之间存在寄生关系。     

用原子-有限元法研究铁中裂纹的低温脆性解理扩展

运用原子 -有限元法 (FEAt)研究了裂纹在低温加载条件下的脆性解理扩展。原子模拟结果表明 :在低温和一定外部载荷条件下 ,bcc- Fe中 { 10 0 } <0 11>边界 I型裂纹的扩展过程是一个裂尖原子键断裂与层错或孪晶扩展相伴随的过程。裂纹低温脆性解理扩展的最大速率可达到 112 5m /s,即约为 0 .6 VR。相应的有限元分析表明 ,裂尖存在较大的能量和应力集中 ,这是导致裂尖原子键断裂及弹性孪晶形成的原因。     

铝电解槽中Marangoni对流研究

Marangoni对流是由界面张力梯度引发的,通常发生在界面张力存在梯度的多相流中.铝电解槽内熔体运动是典型的两相流问题.为此,从工业电解槽中电解质内酸度分析出发,指出该界面上界面张力存在梯度.正是这个梯度引发了铝电解槽中的Marangoni对流.在FLUENT环境下,建立了简单的铝电解槽二维两相流模型对Marangoni对流进行数值模拟.结果表明,电解质/铝液界面张力梯度引发的Marangoni对流对铝电解槽熔体运动和界面变形的影响可以忽略.     

温度对合金塑性变形行为影响的蒙特卡罗模拟

通过蒙特卡罗方法分别模拟研究了在一定的外力、不同温度下,合金材料塑性变形时位错与溶质原子的交互作用。结果表明:随着温度的提高,位错具有更高的能量,位错运动整体呈现出加剧现象,溶质原子愈发难以对位错形成有效钉扎;在一定的外力作用下,温度的提高可以引起位错运动速度的增加,在宏观上即提高材料变形的应变率。     

铝钇共晶反应及其产物对亚共晶铝硅合金初生相的细化研究

研究了稀土Y在亚共晶铝硅合金中诱发稀土-铝共晶反应对铝合金初生α相的细化效应;应用Bramfitt提出的方法,计算了Al-Y共晶反应产物Al3Y与α-Al界面的二维点阵错配度,结果显示两者的二维错配度<6%,即Al3Y可作为α-Al的异质形核质点,且能达到中等有效形核而起到细化晶粒的作用,并通过实验验证计算结果如下:选用稀土元素Y作为A356合金细化剂的同时,将A356-Y熔体分别在稀土钇-铝共晶温度上、下10℃左右保温2 min后快速冷却,获得试样的金相组织照片后利用图像分析工具得到A356-Y合金初生α相的平均晶粒尺寸和平均形状因子。实验结果表明:A356-Y合金在Al-Y共晶温度之下保温,可获得较理想的初生α相形貌和较小的晶粒尺寸;结合二维错配的计算结果,可推断初生α相细化的主要原因为异质形核质点的增加:Al-Y共晶反应产物Al3Y与α-Al的二维点阵错配度在中等有效形核范围内,具有细化合金初生α相的作用;另一共晶产物α-Al与初生α相具有相同的晶体结构和点阵常数,则其也可作为异质形核质点而起到细化合金的作用。稀土Y可作为半固态A356合金中初生α相的优质细化剂。     

Effects of bond coat misfit strains on the rumpling of thermally grown oxides

One factor governing the durability of thermal barrier systems is the concurrent thickening and elongation of the thermally grown oxide (TGO) upon temperature cycling. The elongation can cause cyclic rumpling of the TGO: influenced by oxide growth, bond coat phase transformations, substrate-bond coat interdiffusion, and constituent strengths. The individual effects of these phenomena cannot be understood by experiment alone. In the current study, simulations are conducted to isolate the effects of the misfit strains between the bond coat and substrate. These strains originate from thermal expansion mismatch, phase transformations, and bond coat swelling. For each calculation, the response of the system throughout an individual thermal cycle is linked to the stresses in the bond coat and TGO. Results obtained for representative misfit strains indicate that all three sources promote rumpling during the early stages, while phase transformations and thermal expansion mismatch are more prevalent upon extended cycling. These misfits also induce tensile stresses in the oxide large enough to cause cracking at high temperature. Further analysis has been used to assess the benefits of developing bond coats having lower phase transformation temperature, higher strength, and a more closely matched coefficient of thermal expansion.     

High refractory, low misfit ru-containing single-crystal superalloys

Single-crystal Ru-containing nickel-base superalloys with spherical γ′ precipitates have been observed in alloys with substantial amounts of Re and W and high levels of Ru. The γ′ precipitates did not experience stress-induced shape changes (rafting) during creep deformation at 950 °C and 290 MPa, indicative of a γ-γ′ lattice misfit very near zero. Furthermore, interfacial dislocation networks were not formed during creep deformation in the low misfit alloys. The alloys containing spherical precipitates had lower creep strengths than the alloys containing cuboidal precipitates at 950 °C and 290 MPa. Element partitioning between the phases was investigated in order to determine the origin of the unusual microstructural features. Transmission electron microscopy (TEM)-based energy-dispersive spectroscopy (EDS) analysis of the γ and γ′ phases indicates that Ru affects the partitioning of Re, which partitions much less strongly to the matrix than previously observed in Re-containing superalloys, consistent with a lattice misfit very near zero. With high levels of Ru, the addition of Cr also has a strong influence on partitioning. These investigations demonstrate that Ru and Cr control the lattice misfit, precipitate shape, and creep behavior, through the associated changes in the γ-γ′ phase equilibrium.     

Measurement of the lattice misfit of the nickel-base superalloy SC16 by high-energy synchrotron radiation

High-energy, high-resolution synchrotron radiation diffraction was successfully used to measure the lattice misfit in the single-crystal nickel-base superalloy SC16. A three-peak model, one belonging to the precipitate phase γ′ and two to the matrix γ, was used to fit the diffraction peaks. Room-temperature (RT) contour plots and a temperature scan up to 1170 K revealed that the misfit evolves together with the measured thermal expansion difference between the γ and γ′ phases. This suggests that the origin of the misfit lies in the different thermal expansion coefficient of the two phases. The misfit was found to be positive at RT and to evolve toward negative values as the temperature increases.     

The role of intruder dislocations in modifying the misfit dislocation structures and growth kinetics of precipitate plates

Intruder dislocations formed at θ’ and η plates in Al-4 pet Cu and Al-0.2 pct Au alloys respectively by a small plastic strain partially compensate the misfit by single arrays ; the Burgers vector of the dislocations has a component normal to the plate interfaces. On subsequently aging such deformed microstructures, little change takes place in θ’ where the misfit is low. In η, on the other hand, the large misfit is sufficient to nucleate other compensatory arrays which interact with the intruder dislocations to form the lowest energy dislocation network and to annihilate the Burgers vector component directed normal to the plates. The lengthening kinetics of θ’ plates are unaffected by the intruder dislocations, but the thickening kinetics are briefly accelerated, probably by means of vacancy-enhanced diffusion associated with the plastic deformation. The thickening enhancement later falls off as the defects are annealed. In Al-Au, an interesting morphological instability develops and leads to the formation of elongated plates. These we believe are caused by a mechanism of sympathetic nucleation. R. Sankaran, formerly Department of Metallurgy and Materials Science, University of Pennsylvania, Philadelphia, Pa. 19174     

Effect of cyclic plasticity on internal stresses in a metal matrix composite

Neutron diffraction has been used to measure the elastic strains in a silicon carbide particle-reinforced aluminum alloy during cyclic plasticity. Strains were recorded in both phases of the material, in sufficient directions to allow for calculation of the internal stresses. The shape misfit stress in the composite was calculated from the macroscopic stress data using an Eshelby-based model. Changes in the misfit stress caused by plastic deformation can be clearly observed. Local plastic anisotropy of the matrix material is also seen and was monitored by comparing results from the two diffraction planes, {111} and {200}, that were measured. The results have been compared to those obtained using an elasto-plastic self-consistent modeling approach, which shows the evolution of load sharing between the matrix and reinforcement, as well as the origin of the plastic anisotropy strains in the aluminum.     

The influence of coherency strain on the elevated temperature tensile behavior of Ni-15Cr-AI-Ti-Mo alloys

The effect of coherency strain on elevated temperature tensile strength was examined in a model, two-phase y’-strengthened Ni-15Cr-Al-Ti-Mo alloy series. The temperature dependence of coherency strain as represented by the γ-γ’ mismatch was determined over the temperature range 25 to 800 °C. The flow stress incrementAσ _γ, due to precipitation of γ’, was found to correlate well to the magnitude of the γ-γ’ mismatch over the same temperature interval. The correlation was strongest for high misfit alloys regardless of the Antiphase Boundary Energy (APBE). The predominance of by-pass type dislocation-particle interactions in high coherency alloys confirms that strengthening is primarily due to coherency strains. Conversely, alloys with low misfit exhibit two distinct particle shear mechanisms believed to be dependent upon the relative APBE and matrix stacking fault energy of the alloy.     

Structural ledges in interphase boundaries

This article addresses the properties of stepped misfitting interfaces and their energetic preference to planar misfitting interfaces. It highlights: (a) the purely geometrical or rigidlike, (b) the rigid (unrelaxed) energetic, and (c) the relaxed energetic properties of stepped interfaces. In (a), we address (1) the accommodation of misfit by the step or ledge mode through the cancellation of the mismatch, that builds up along a terrace, by the forwardpattern advance effected by a step,i.e., the relative displacement of atomic patterns on either side of the interface as observed in crossing a structural ledge along the interface, (2) the sideways (shear) pattern advance which seems to be energetically undesirable, (3) the need for tilt-type misfit dislocations to accommodate the misfit normal to the interface, and (4) the fact that at {III}_fcc(face-centered cubic)/{110}_{bcc(body-centered cubic) interfaces with rhombic symmetries, the misfits, as well as the pattern advances, are interrelated through the ratior = b/a of nearest-neighbor distances in the crystals. In (b), we exploit the rigid model approach that (1) yields ideality criteria for minimum energy and provides energetic justification for the step mode of misfit accommodation, (2) confirms that the average terrace widthl[inx} defined by this mode also meets the condition for positive energy gain, and (3) defines the upper and lower energy bounds to provide a perspective of the system energetics. In (c), the foregoing considerations are refined by a transition to the harmonic (elastic) model to yield (1) the dependence of the mean energy per atom of a stepped interface on interfacial misfit and pattern advance, as well as the dependence of the mean energy per atom of a planar interface on misfit, (2) expressions for the stresses related to the atomic interaction between opposing terraces, (3) atomic displacements that might be probed by modern analytical techniques, and (4) resolved shear stresses and normal stresses that may facilitate the formation of glide dislocations in the presence of applied stresses. The boundary in a two-dimensional space—spanned by misfit and pattern advance—between regions where stepped interfaces are more stable than planar ones has been determined, suggesting that a critical misfit exists above which only planar interfaces are stable. Whereas the resolved shear stress related to the formation of structural ledges may facilitate the formation of dislocations in the presence of a subcritical applied stress, the corresponding displacements (bending) of atomic planes are probably observable only with strain contrast electron microscopy techniques. Formerly with the Physics Department, University of Pretoria. Formerly Visiting Scientist, Physics Department, University of Pretoria, Pretoria, South Africa. This paper is based on a presentation made in the symposium “The Role of Ledges in Phase Transformations” presented as part of the 1989 Fall Meeting of TMS-MSD, October 1–5, 1989, in Indianapolis, IN, under the auspices of the Phase Transformations Committee of the Materials Science Division, ASM INTERNATIONAL.     

New frontiers in thin film growth and nanomaterials

This article reviews recent developments in thin film growth and formation of three-dimensional epitaxial nanostructures. First, we present a unified standard model for thin film epitaxy, where single-crystal films with small and large lattice misfits are grown by a new paradigm of domain matching epitaxy (DME). We define epitaxy as having a fixed orientation rather than the same orientation with respect to the substrate. The DME involves matching of integral multiples of lattice planes (diffracting as well as nondiffracting) between the film and the substrate, and this matching could be different in different directions. The idea of matching planes is derived from the basic fact that during thin film growth, lattice relaxation involves generation of dislocations whose Burgers vectors correspond to missing or extra planes, rather than lattice constants. In the DME framework, the conventional lattice matching epitaxy (LME) becomes a special case where matching of lattice constants results from matching of lattice planes with a relatively small misfit of less than 7 to 8 pct. In large lattice mismatch systems, we show that epitaxial growth of thin films is possible by matching of domains where integral multiples of lattice planes match across the interface. We illustrate this concept with atomic-level details in the TiN/Si(100) with 3/4 matching, the AlN/Si(100) with 4/5 matching, and the ZnO/α-Al₂O₃(0001) with 6/7 matching of lattice planes across the film/substrate interface. By varying the domain size, which is equal to the integral multiple of lattice planes, in a periodic fashion, it is possible to accommodate additional misfit beyond the perfect domain matching. Thus, we can potentially design epitaxial growth of films with any lattice misfit on a given substrate with atomically clean surfaces as long as there is wetting or finite interatomic interaction across the interface and cores of dislocations do not overlap. In-situ X-ray diffraction studies on initial stages of growth of ZnO films on sapphire correctly identify a compressive stress and a rapid relaxation within one to two monolayers, consistent with the DME framework and the fact that the critical thickness is less than a monolayer. The DME examples ranging from the Ge-Si/Si(100) system with 49/50 matching (2 pct strain) to metal/Si systems with 1/2 matching (50 pct strain) are tabulated, strategies for growing strain-free films by engineering the misfit to be confined near the interface are presented, and the potential for epitaxial growth of films with any lattice misfit on a given substrate with atomically clean surfaces is discussed. In the second part, we discuss the formation of epitaxial nanodots/nanocrystals in crystalline matrices such as MgO and TiN. The formation Ni nanocrystals inside MgO involves lattice misfit ranging from 3.0 to 31.3 pct, and the formation of Ni nanocrystals in TiN has a misfit of about 17 pct. To form epitaxial nanodots, we use DME framework to grow nanodots inside crystalline matrices. Growth characteristics and crystallography of nanodots are controlled to enhance the overall properties of nanostructured materials. We illustrate this for nanostructured magnetic materials where coercivity and blocking temperature can be considerably enhanced by controlling the orientation for magnetic memory and storage applications, among others. In the last part, the DME principles are applied to grow self-assembled epitaxial nanodots using pulsed laser deposition. By controlling the clustering kinetics, it is possible to obtain a uniform distribution of epitaxial nanodots and overcome thermodynamically driven Ostwald ripening. This process allows the formation of epitaxial nanostructures via three-dimensional self-assembly, the “holy grail” of nanostructured materials processing, leading to unique and novel properties. Jagdish (Jay) Narayan holds The John C.C. Fan Family Distinguished Chair Professorship and is Director of the NSF Center for Advanced Materials and Smart Structures at North Carolina State University. The Edward DeMille Campbell memorial lecture entitled, “New Frontiers in Thin Film Growth and Nanomaterials,” was delivered at the Annual ASM International Meeting (October 17–20, 2004) in Columbus, Ohio. Professor Narayan received his M.S. (1970) and Ph.D. (1971) degrees in a record time of two years from the University of California, Berkeley, after his Bachelor’s of Technology with Distinction and Highest Honors from IIT, Kanpur in 1969. Professor Narayan has had a profound impact on our understanding of defects and interfaces in thin film heterostructures, laser-solid interactions and processing of novel materials, controlled thin film growth and self-assembled nanostructures, and nanoscale characterization and modeling of new materials and properties. He invented novel supersaturated semiconductor alloys formed by solid phase epitaxy, and by liquid-phase crystallization where melt-quenching rates are billions of degrees per second. This research, featured twice in Science Magazine, has resulted in numerous U.S. patents and three IR-100 Awards. More recently, Narayan has pioneered and patented a new concept of domain epitaxy, where an integral number of lattice planes of the film match that of the substrate in large lattice mismatched systems. The domain epitaxy is key to the formation of thin film heterostructures, such as TiN films on silicon with 4/3 matching, and III-nitrides and ZnO films on sapphire with 6/7 matching. Narayan invented new cubic ZnMgO alloys, which can be grown epitaxially on silicon (100) substrates for integrating optoelectronic and spintronic devices. Narayan discovered and patented a new method of self-assembly for processing nanostructured magnetic, photonic, electronic, and structural materials. His discoveries with Dr. John Fan, Kopin Corporation, related to domain epitaxy and quantum confinement by thickness variation (creating nanopockets) are being used by Kopin Corp. to manufacture high-efficiency light emitting diodes for solid-state lighting. He has published over 800 scientific articles, edited 9 books, and received 22 patents pertaining to novel materials and processing methods, domain epitaxy, and a new class of next-generation semiconductor alloys. He is a Fellow member of APS, AAAS, ASM International, TMS, and MRS-I. He has won numerous other honors, including three IR-100 Awards and a 1999 ASM Gold Medal. He also received Distinguished Alumnus Honors from IIT/K in 1997.     

New frontiers in thin film growth and nanomaterials

This article reviews recent developments in thin film growth and formation of three-dimensional epitaxial nanostructures. First, we present a unified standard model for thin film epitaxy, where single-crystal films with small and large lattice misfits are grown by a new paradigm of domain matching epitaxy (DME). We define epitaxy as having a fixed orientation rather than the same orientation with respect to the substrate. The DME involves matching of integral multiples of lattice planes (diffracting as well as nondiffracting) between the film and the substrate, and this matching could be different in different directions. The idea of matching planes is derived from the basic fact that during thin film growth, lattice relaxation involves generation of dislocations whose Burgers vectors correspond to missing or extra planes, rather than lattice constants. In the DME framework, the conventional lattice matching epitaxy (LME) becomes a special case where matching of lattice constants results from matching of lattice planes with a relatively small misfit of less than 7 to 8 pct. In large lattice mismatch systems, we show that epitaxial growth of thin films is possible by matching of domains where integral multiples of lattice planes match across the interface. We illustrate this concept with atomic-level details in the TiN/Si(100) with 3/4 matching, the AlN/Si(100) with 4/5 matching, and the ZnO/α-Al₂O₃(0001) with 6/7 matching of lattice planes across the film/substrate interface. By varying the domain size, which is equal to the integral multiple of lattice planes, in a periodic fashion, it is possible to accommodate additional misfit beyond the perfect domain matching. Thus, we can potentially design epitaxial growth of films with any lattice misfit on a given substrate with atomically clean surfaces as long as there is wetting or finite interatomic interaction across the interface and cores of dislocations do not overlap. In-situ X-ray diffraction studies on initial stages of growth of ZnO films on sapphire correctly identify a compressive stress and a rapid relaxation within one to two monolayers, consistent with the DME framework and the fact that the critical thickness is less than a monolayer. The DME examples ranging from the Ge-Si/Si(100) system with 49/50 matching (2 pct strain) to metal/Si systems with 1/2 matching (50 pct strain) are tabulated, strategies for growing strain-free films by engineering the misfit to be confined near the interface are presented, and the potential for epitaxial growth of films with any lattice misfit on a given substrate with atomically clean surfaces is discussed. In the second part, we discuss the formation of epitaxial nanodots/nanocrystals in crystalline matrices such as MgO and TiN. The formation Ni nanocrystals inside MgO involves lattice misfit ranging from 3.0 to 31.3 pct, and the formation of Ni nanocrystals in TiN has a misfit of about 17 pct. To form epitaxial nanodots, we use DME framework to grow nanodots inside crystalline matrices. Growth characteristics and crystallography of nanodots are controlled to enhance the overall properties of nanostructured materials. We illustrate this for nanostructured magnetic materials where coercivity and blocking temperature can be considerably enhanced by controlling the orientation for magnetic memory and storage applications, among others. In the last part, the DME principles are applied to grow self-assembled epitaxial nanodots using pulsed laser deposition. By controlling the clustering kinetics, it is possible to obtain a uniform distribution of epitaxial nanodots and overcome thermodynamically driven Ostwald ripening. This process allows the formation of epitaxial nanostructures via three-dimensional self-assembly, the “holy grail” of nanostructured materials processing, leading to unique and novel properties. Jagdish (Jay) Narayan holds The John C.C. Fan Family Distinguished Chair Professorship and is Director of the NSF Center for Advanced Materials and Smart Structures at North Carolina State University. The Edward DeMille Campbell memorial lecture entitled, “New Frontiers in Thin Film Growth and Nanomaterials,” was delivered at the Annual ASM International Meeting (October 17–20, 2004) in Columbus, Ohio. Professor Narayan received his M.S. (1970) and Ph.D. (1971) degrees in a record time of two years from the University of California, Berkeley, after his Bachelor’s of Technology with Distinction and Highest Honors from IIT, Kanpur in 1969. Professor Narayan has had a profound impact on our understanding of defects and interfaces in thin film heterostructures, laser-solid interactions and processing of novel materials, controlled thin film growth and self-assembled nanostructures, and nanoscale characterization and modeling of new materials and properties. He invented novel supersaturated semiconductor alloys formed by solid phase epitaxy, and by liquid-phase crystallization where melt-quenching rates are billions of degrees per second. This research, featured twice in Science Magazine, has resulted in numerous U.S. patents and three IR-100 Awards. More recently, Narayan has pioneered and patented a new concept of domain epitaxy, where an integral number of lattice planes of the film match that of the substrate in large lattice mismatched systems. The domain epitaxy is key to the formation of thin film heterostructures, such as TiN films on silicon with 4/3 matching, and III-nitrides and ZnO films on sapphire with 6/7 matching. Narayan invented new cubic ZnMgO alloys, which can be grown epitaxially on silicon (100) substrates for integrating optoelectronic and spintronic devices. Narayan discovered and patented a new method of self-assembly for processing nanostructured magnetic, photonic, electronic, and structural materials. His discoveries with Dr. John Fan. Kopin Corporation, related to domain epitaxy and quantum confinement by thickness variation (creating nanopockets) are being used by Kopin Corp. to manufacture high-efficiency light emitting diodes for solid-state lighting. He has published over 800 scientific articles, edited 9 books, and received 22 patents pertaining to novel materials and processing methods, domain epitaxy, and a new class of next-generation semiconductor alloys. He is a Fellow member of APS, AAAS, ASM International, TMS, and MRS-I. He has won numerous other honors, including three IR-100 Awards and a 1999 ASM Gold Medal. He also received Distinguished Alumnus Honors from IIT/K in 1997.