绪论60583.pptVIP

材料科学基础Fundamentals of Materials Science 安徽工业大学 材料科学基础 是研究材料的成分、组织结构、加工工艺与性能之间关系 的科学。 * 绪 论 0.1 材料的基本特征 What are Materials? Materials are everywhere! Look around 材料是国民经济的物质基础。 广义的材料包括人们的思想意识之外的所有物质 材料无处不在，无处不有 材料的基本特征： 多样性：金属材料、陶瓷材料、高分子材料、 复合材料 相似性：转变机理、缺陷行为、平衡热力学、扩散、流变和断裂机理、精细结构与界面行为等 交叉性：物理、化学、冶金、工程等 材料的一般分类 金属: 一般是由金属元素组成的材料，金属往往是较好的导热体和导电体，具有高的强度和好的延展性，抛光后具有金属光泽。 陶瓷: 一般是由金属元素和非金属元素或非金属元素之间组成的化合物，如氧化物、氮化物、碳化物，具有很好的耐高温性能等。 高分子（塑料）: 一般是基于C、H元素的有机化合物，具有非常大的分子结构，往往具有很低的密度，而且在高温时不稳定。 复合材料: 由两个或两个以上类型的材料组成的复合体，如金属基复合材料、陶瓷基复合材料、塑料基复合材料。 其它材料: 如半导体材料等电子材料，等等。 0.2 材料的发展历史 Stone age Bronze age Cast iron Steel Aluminum Composites Fibers rapid evolution High temperature ceramic, superconductors, etc. 石器时代Stone age 青铜器时代Bronze age 铁器时代Iron age 0.3 材料的关键要素 1 加工 Processing: How can I produce this product 凝固 Solidification Processing utilizes the liquid state in the process The structural processing of most metals begins by forming an alloy in the molten state, where it is relatively easy to mix the components. This process is also utilized in glasses and some polymers. Once the proper temperature and composition is achieved, the melt is cast. 粉末加工 Powder Processing utilizes powders in the process Slip casting, powder pressing, hydroplastic forming followed by drying and firing or hot pressing- Bulk ceramics are usually processed in powder form since their high melting points and low formability prohibit solidification and/or deformation processing. Metals and polymers can also be processed from powders. 沉积 Deposition Processing utilizes evaporation and/or condensation in the process Electroplating, spray coating, sputtering, laser ablation, chemical vapor deposition CVD , PVD, etc. - Deposition processing is a chemical surface modification such as used in semiconductor processing or for decorative or protective coatings generally involves the deposition of a chemical vapor or ions onto a surface. Vapor source methods require a vacuum