Mr. Rogers' IB Design Technology Objectives


IB properties/materials matrix
  Timber Metals Ceramics Plastics Textile Fibers Food Composites
Physical properties              
Density low high medium low low low  
Electrical resistivity high v. low  v. high high high medium  
Thermal conductivity low  v. high v. low low low medium  
Thermal expansivity low high v. low low - v. high low medium  
Hardness medium medium - v. high  v. high low - medium low low  
Mechanical properties              
Tensile strength medium high
(Here the IB syllabus is wrong. Ceramics have low to v.high tensile strengths)
low - medium medium

(The fiber use in bullet proof vests have high tensile strengths)

low - medium  
Stiffness medium high  v. high  low - medium v. low  low - medium  
Toughness high  v. high  v. high medium medium low - medium  


Not required on next test Required on next test