1) Composites
Composed of more than one material type – one: matrix; other(s): reinforcing addition
Matrix – polymeric, metallic, or ceramic materials
Reinforcing addition: glass fibers, carbon fibers, ceramic fibers (e.g. basalt fibers) or nanoparticles (e.g. SiC, SiN, etc)
To modify existing materials and develop new materials, we need to know MSE
Classification of materials
In terms of chemical makeup and atomic structure Metals; Ceramics; Polymers
2材料科学基础英文版课件_(8)
Assessment Structure
• Written examination (50%) • Oral presentation (20%, any topics in
Chapter 7 – Mechanical Properties, 4 students as a group, 15 minutes) • Report (20%, any topics in materials science and engineering) • Assignment (10%)
What is materials science and engineering
• Materials science Concerned with the relationship between
composition, structure and properties of materials • Materials engineering
3) Polymeric: organic compounds based on carbon, hydrogen and other nonmetallic elements – plastics and rubbers Normally low density and relatively flexible
Concerned with designing or engineering the structure to produce a predetermined set of properties
The structure of a material depends on what composition it has and how it is processed. Also, the performance of a material is a function of its properties • MSE: Composition-processing-structureproperties-performance relationship
Designed to display a combination of the best properties of each of the components
2) Semiconductors
Electrical properties being intermediate between conductors and insulators and being very sensitive to their composition and environmental conditions (e.g., functional ceramics: microwave dielectric ceramics, ferroelectric and piezoelectric ceramics)
2) Ceramic: compounds between metallic and nonmetallic elements – oxides, nitrides, and carbides Very insulative to electricity and heat – very low electrical and thermal conductivities Highly resistant to high temperatures and corrosive environments Very hard but very brittle
Additional types of material
Composites; Semiconductors; and Biomaterials
They originate from the three basics (metals, ceramics and polymers), but they have special us study materials science and engineering
All applied scientists and engineers in any engineering areas: design problems involving materials
To select a right material from many thousands according to service conditions and property requirements, we need to have the knowledge of MSE
1) Metallic: combinations of metallic elements Free electrons – good electrical and thermal conductivities Strong but deformable – extensive use in structural applications