图 Georgia山utute ofTechnology The evolution of structural materials 105 Strength-Density 1900AD 104 Ceramics Steeis Metals and glasses 103 Bronze Polymers Leather Wto gran Gold 102 Natural materials F William McKinley 1897-1901 10 Stone Copper Zinc Tin Lead Pottery I togran Concrete 0.1- 0.01 0.01 0.1 1 10 100 Density.p (Mg/m3) 材料科学与工程学院 5 School of Materials Science and Engineering材料科学与工程学院 School of Materials Science and Engineering 5