熔体过热处理对定向凝固界面形态及稳定性的影响

介绍了固液界面形态及稳定性的判据,即成分过冷理论和绝对稳定理论;简述了国内熔体过热处理的研究;详细阐述了熔体过热处理影响定向凝固界面形态及稳定性的现象及理论研究.并对今后熔体过热处理在定向凝固技术中的研究方向作了展望.     

KINETICS OF LIQUID PENETRATING INTO GRAIN BOUNDARY

ＫＩＮＥＴＩＣＳＯＦＬＩＱＵＩＤＰＥＮＥＴＲＡＴＩＮＧＩＮＴＯＧＲＡＩＮＢＯＵＮＤＡＲＹ￥Ｃｈｅｎ，Ｋａｎｇｈｕａ；Ｈｕａｎｇ，Ｂａｉｙｕｎ（ＰｏｗｄｅｒＭｅｔａｌｌｕｒｇｙＲｅｓｅａｒｃｈｉｎｓｔｉｔｕｔｅ，ＣｅｎｔｒａｌＳｏｕｔｈＵｎｉｖｅｒｓｉ...     

复合材料凝固过程中的颗粒/界面行为数学模型

根据颗粒增强金属基复合材料凝固过程中的颗粒 /界面作用微观机理 ,导出颗粒附近温度场 ,液 /固界面形状 ,颗粒受力情况及颗粒吞并 /推移临界条件数学模型。分析了热导率、颗粒尺寸和凝固速度不同对颗粒 /界面行为的影响。     

反向凝固与高温轧制过程中元素互扩散对复合界面的作用

在反向凝固与高温轧制过程中 ,母带与凝固层间一直进行着互扩散 ,C元素靠反应扩散由母带扩散到凝固层 ,Cr由凝固层扩散到母带 ,母带与凝固层之间存在明显的扩散层。Cr在母带中的扩散厚度约为 13μ。扩散到母带中的Cr和母带中的Fe形成固溶体 ,并析出Cr的碳化物。母带与凝固层界面实现了冶金结合     

气液并流吸收过程中液相近界面浓度分布的全息干涉测量

1 INTRODUCTION Mass transfer across free interface of gas-liquid flow is of extensive importance and is encountered in most industrial applications. A close investigation of concentration distribution near the interface is helpful to understand mass transfer phenomena, to guide the development of transport theories, and to optimize the design of gas-liquid contact equipment. Laser holographic interference technique provides a precise and noncontact measurement method for measuring the tran…     

A novel method for high-resolution imaging of coating distribution within a rough-textured plywood surface

A new method was developed which enabled us to obtain high-resolution images of the distribution of an oil-borne stain in a saw-textured plywood surface. The method involved treating 90 μm thick plywood sections, which had been cut transversely through the wood-coating interface using a sliding microtome, with osmium tetroxide (OsO₄) prior to examination with a field-emission scanning electron microscope (FE-SEM) operating in backscattered electron imaging (BEI) mode. The combination of OsO₄ staining and use of FE-SEM-BEI afforded excellent contrast differentiation between the coating and wood cell walls, revealing coating penetration into even nano-size cell wall cracks and delaminations formed during band-sawing of the plywood. The novel technique described adds a new dimension to probing wood–coating interface.     

Numerical analysis of galvanic corrosion of Zn/Fe interface beneath a thin electrolyte

A numerical analysis of galvanic corrosion of a Zn/Fe interface beneath a thin layer electrolyte is presented. Specifically, a circular defect, where the zinc coating has been removed, is considered. It is assumed that both oxygen reduction and iron oxidation can occur on the Fe surface, while only zinc oxidation occurs on the Zn surface. The importance of electrolyte thickness and conductivity and defect radius is considered. It is assumed that the iron and zinc oxidation rates are described by a Tafel relationship. If the kinetic parameters of the oxidation reactions are known, the cathodic protection of Fe is a function of a Wagner number, the ratio of the electrolyte thickness to the defect radius, and the ratio of the radius of the defect to the outer radius of the zinc layer.     

树脂传递模塑工艺中工艺参数对树脂-纤维界面的影响

本文系统研究了工艺参数对由树脂传递模塑成型的复合材料的拉伸强度和树脂-纤维界面的影响.这些参数包括注射压力和模腔/纤维毡的温度.在较低的注射压力和较高的成型温度下,纤维得到良好的浸润和粘结,成型复合材料的拉伸强度也较高.     

斜板沉降器的设计

简要叙述了流离倾斜斜板的层膜上的单个液滴的基本聚结原理。着重介绍重力沉降器的设计方法，并指出在设计过程中可能出现的错误。     

材料化学工程科学内涵及方法初探:从介观尺度界面流体行为出发认知材料

作为一门新兴的交叉学科,材料化学工程科学内涵的进一步凝练和方法论的建立显得十分重要和迫切。介观尺度下界面流体的研究对于材料化学工程具有重要意义,材料化学工程的科学内涵在于通过认识介观尺度下界面处流体行为来"认知"材料,以期建立材料结构、性能(应用)与制备(生产)三者之间的关系。其中,弄清介观尺度下复杂作用和复杂结构对界面流体行为的影响,是"认知"材料的关键。分子模拟技术作为单因素遴选介观尺度各影响因素的有效手段,在实际应用中存在两大难点:如何同时获得界面流体反应和传递两个方面的信息;如何实现分子层面认识在材料应用层面的转化。基于此,初步讨论了材料化学工程研究方法的发展趋势。