notes/mechanical/mmme1029_materials.md

author	date	title	tags
Alvie Rahman	\today	MMME1029 // Materials	uni nottingham mmme1029 materials

Lecture 1 (2021-10-04)

1A Reading Notes

Classification of Energy-Related Materials

• Passive materials---do not take part in energy conversion e.g. structures in pipelines, turbine blades, oil drills

• Active materials---directly take part in energy conversion e.g. solar cells, batteries, catalysts, superconducting magnests

• The material and chemical problems for conventional energy systems are mostly well understood and usually associated wit structural and mechanical properties or long standing chemical effects like corrosion:

  • fossil fuels
  • hydroelectric
  • oil from shale and tar
  • sands
  • coal gasification
  • liquefaction
  • geothermal energy
  • wind power
  • bomass conversion
  • solar cells
  • nuclear reactors

Applications of Energy-Related Materials

High Temperature Materials (and Theoretical Thermodynamic Efficiency)

• Thermodynamics indicated that the higher the temperature, the greater the efficiency of heat to work:

  = \frac{T_{high}-T_{low}}{T_{high}} (in kelvin)

• The first steam engines were only 1% efficient, while modern steam engines are 35% efficient primarily due to improved high-temperature materials.

• Early engines made from cast iron while modern engines made from alloys containing nickel, molybdenum, chromium, and silicon, which don't fail at temperature above 540 \textdegree{}C

• Modern combustion engines are nearing the limits of metals so new materials that can function at even higher temperatures must be found--- particularly intermetallic compounds and ceramics are being developed

Types of Stainless Steel

• Type 304---common; iron, carbon, nickel, and chromium
• Type 316---expensive; iron, carbon, chromium, nickel, molybdenum

Self Quiz 1

1. What is made of billion year old carbon + water + sprinkling of stardust?

   Me

2. What are the main classifications of metals?

   Metals, glass and ceramics, plastics, elastomers,

3. [There are] Few Iron Age artefacts left. Why?

   They rusted away

4. What is maens by 'the micro-structure of a material'?

   The very small scale structure of a material which can have strong influence on its physical properties like toughness and ductility and corrosion resistance

5. What is a 'micrograph' of a material?

   A picture taken through a microscope

6. What microscope is used to investage the microstructure of a material down to a 1 micron scale resolution?

   Optical Microscope

7. What microscope is used [to investigate] the microstructure of a material down to a 100 nm scale resolution?

   Scanning Electron Microscope

8. What length scales did you see in the first slide set?

   1 mm, 0.5 mm, 1.5 \textmu{}m

9. What material properties were mentioned in the first slide set?

   Hardness, brittleness, melting point, corrosion, density, thermal insulation

Self Quiz 2

1. What is the effect of lowering the temperature of rubber?

   Makes it more brittle, much less elastic and flexible

2. What material properties were mentioned in the second slide set?

   Young's modulus, specific heat, coefficient of thermal expansion