1. Chapter 12 Case Studies: Hybrids
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

2. Metal Matrix Panel
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

3. Figure 12.1
Possible magnesium-matrix composites. The lozenges show the areas bracketed by the upper and lower bounds of Table The green areas within them extend up to a volume fraction of 0.5.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

4. Flexible Conductors and Percolation
Figure 12.2
When conducting particles or fibers are mixed into an insulating elastomer, a hole in the material-property space is filled. Carbon-filled butyl rubbers lie in this part of the space.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

5. Extreme Combinations of Thermal and Electrical Conduction
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

6. Figure 12.3
Two alternative configurations of copper and polyethylene, shown here in two dimensions but easily generalized to three. The one on the left has high electrical conductivity but low thermal conductivity; the one on the right has the opposite.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

7. Figure 12.4
Two alternative hybrid configurations of copper and polyethylene give very different combinations of thermal and electrical conductivity, and create new “materials” with properties that are not found in homogenous materials.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

8. Refrigerator Walls Figure 12.5
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

9. Figure 12.6
The blue L-shaped trajectory plots the performance of steel-faced, PVC foam cored sandwiches. The thermal performance is plotted on the vertical axis, the mechanical performance on the horizontal one. Both are to be minimized.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

10. Materials for Microwave-Transparent Enclosures
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

11. Figure 12.7
A plot of flexural modulus and dielectric constant for low dielectric constant materials. The trajectory shows the possibilities offered by hybrids of GFRP and polymer foam.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

12. Connectors That Don’t Relax Their Grip
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

13. Figure 12.8
A hybrid connector. We seek materials with matching thermal expansion, one of which retains strength and stiffness well above 200 C. Copper is chosen for Material 1 because of its excellent electrical conductivity. Type 302 or 304 stainless steel is a good choice for Material 2.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

14. Figure 12.9
The connector has two job – to conduct and to exert a clamping force that does not relax. High-conductivity copper and 304 stainless steel are both much cheaper than Cu 2% Be. Roll-bonding them will of course add cost, but in large volume production it could be competitive – and it solves the relaxation problem
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

15. Heat Spreading Surfaces
Figure 12.10
A bilayer of copper and stainless steel creates a “material” with good conductivity and an anisotropy ratio greater than 6
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

16. Mechanical Efficiency of Natural Materials
The stiffness, strength, and toughness of wood derive largely from the stiffness, strength, and toughness of the cellulose molecule.
Figure 12.11
The hierarchical
structure
of wood
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

17. Hierarchical Structure of Bone
Figure 12.12
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

18. Figure 12.13
A material-property chart for natural materials, plotting Young’s modulus against density. The guide lines identify materials that are light and stiff
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

19. Figure 12.14
A material-property chart for natural materials, plotting strength against density. Guide lines identify those materials which are light and strong.
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

20. Young’s Modulus vs. Strength
Figure 12.15
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby

21. Material property chart for natural materials
Material property chart for natural materials. Guide lines indicate those materials with high stiffness and high toughness
Figure 12.16
Materials Selection in Mechanical Design, 4th Edition © 2010 Michael Ashby