Faculty Awards for Women Scientists and Engineers (FAW)

工程材料的结构-性能关系是P.I.的广泛兴趣领域。目前的工作分为三类：合金和金属基复合材料的凝固加工，有色合金和陶瓷复合材料的增韧机制，以及摩擦材料的结构变化研究。凝固加工领域的分析工作主要集中在合金铸件中微偏析现象的二维模拟上。采用有限元和有限差分技术来研究瞬态温度和成分分布，并确定合金和纯金属的界面形态，包括自然对流效应、模具介质中的蓄热效应以及充型过程中表面波的耗散。这些算法是从质量、动量和能量的第一性原理发展而来的，其结果与文献报道的结果一致。该领域的未来计划包括将这项工作扩展到三维空间，并在凝固模拟过程中在合金的糊状区放置增强纤维。采用分析与实验相结合的方法研究了陶瓷基复合材料的变形增韧机理。有限实验研究的结果被用于复合材料中与单纤维相交的裂纹的二维有限元模型。在第三类中，在摩擦作用过程中，材料经历局部热点，这些热点本身引起材料结构的变化。这些变化的特征及其对制动过程中噪声产生的影响正在使用半金属材料进行研究。

Structure-property relationships in engineering materials is the broad area of interest of the P.I. Current work falls into three categories: solidification processing of alloys and metal-matrix composites, toughening mechanisms in nonferrous alloys and ceramic composites, and the study of the structural changes in friction materials. Analytical work in the area of solidification processing has focused on the two dimensional simulation of the phenomenon of microsegregation in alloy castings. Finite element and finite difference techniques are employed to investigate transient temperature and composition profiles and to determine the interface morphology for alloys and pure metals, including natural convection effects, the heat storage effect in the mold media, and the dissipation of the surface wave during mold filling. The algorithms, developed from first principles of mass, momentum and energy, yield results which agree well with those reported in the literature. Future plans in this area involve the extension of this work to three dimensions and the placement of reinforcing fibers in the mushy zone of the alloy during the solidification simulation. Combined analytical and experimental techniques are employed to study the deformation and toughening mechanism in ceramic matrix composites. The results of the limited experimental investigations are used in the two dimensional finite element model of the crack intersecting a single fiber in the composite. In the third category during the application of friction, the materials experience local hot spots which themselves cause changes in the structure of the materials. The characterization of these changes and their effect on the production of noise during braking are being studied using semimet materials.