Mechanical properties strengthening

The Zn—A1 system permits manipulation of the mechanical properties by suitable heat treatment. The aluminum-rich alpha phase is especially suitable for solution hardening since it can be supersaturated by as much as 30 wt % zinc. Furthermore, both alpha and beta phases can be strengthened by precipitation because of decreasing solute solubiUty with decreasing temperature. 

Mechanical Properties. An advantage of the two corrosion-resistant alloys is that they may be strengthened considerably by cold working. MP35N alloy is iatended for use ia the work-hardened or work-hardened and aged condition, and the manufacturers have suppHed considerable data concerning the mechanical properties of the alloy at different levels of cold work. Some of these data are given ia Table 8. 

Figure 11.7 shows how the mechanical properties of normalised carbon steels change with carbon content. Both the yield strength and tensile strength increase linearly with carbon content. This is what we would expect the FejC acts as a strengthening phase, and the proportion of FojC in the steel is linear in carbon concentration (Fig. 11.6a). The ductility, on the other hand, falls rapidly as the carbon content goes up (Fig. 11.7) because the a-FejC interfaces in pearlite are good at nucleating cracks.

R. Hill, Theory of Mechanical Properties of Fibre-Strengthened Materials - III. Self-Consistent Model, Journal of the Mechanics and Physics of Solids, August 1965, pp. 189-198. 

To strengthen mechanical properties and vary the transition temperature, hydrophobic monomers such as BMA were introduced into poly(IPAAm). The unique swelling properties with varying BMA composition are shown in Figure 11. 

Metals are rarely applied in their pure state. They are most often put to use in the form of alloys that exploit or strengthen desirable properties and overcome characteristics that limit performance. Alloys based on the carbides and nitrides of the transition metals of Groups 4 through 6 of the Periodic Table exhibit special physical and mechanical properties that result from manipulation of composition and manufacturing processes. 

J. S. Benjamin, C. B. Raymond, Nickel-Based Dispersion-Strengthened Alloys, in Mechanical Properties of Metallic Composites Ochiai, S., Ed. Marcel Dekker, 1993. 

---