材料导论总结.docx

模块 2 2-48 ? Solution:A homogeneous mixture of chemically distinct substances that forms a phase 相? Solvent 溶剂: the substance present in the greater amount. ? Solute 溶质: the substance present in the lesser amount ? Mixture 混合物:A material that has no position and contains more than one phase ? Alloy 合金:bination ofa metal and one or more other elements forming either a mixture ora solid solution. ? Plastic alloy 塑料合金: blends of polymers or copolymers with other polymers or elastomers. ? Diffusion: transport of atoms through matter. 2. The intermingling 混合物 in solid materials of atoms ( in metals), ions (in ceramics), or molecules (in polymers). ? Prerequisites for diffusion to occur:1. Adjacent site needs to be empty (vacancy 空位 or interstitial 空隙). 2. Sufficient energy must be available to break bonds and e lattice distortion ? FASTER for... ? open crystal structures ? lower density materials ? materials w/secondary bonding ? lower melting T materials ? smaller diffusing atoms ? Diffusion is affected by :Microstructure of solids, Temperature, Time ? 58. 1. An abundance of line defects (dislocations) strengthen the materials ( Mutual interference in their movement through crystal prevents the planes of atoms from slipping ) presence ofa few dislocation increase the ductility ofa crystalline solid. ? 62. Point defects 点缺陷?1 or2 atom positions ? Affect only the small volume of the crystal surrounding a single lattice site. ? Dislocation :A linear array of atoms along which there is some imperfection in the bonding of the atoms ? Area defect : exist in the form of grain boundaries ( 晶粒边界) 模块 3 ? 1.- Chemical properties are associated with the transformation of one material into another. – Physical properties involve no change in position of the material. – Mechanical properties are defined asa measure ofa material ’s ability to carry or resist mechanical forces or stresses. Mechanical properties ofa material affect how the material can be worked.