Temperature effects elongation

In region 3 of Figures 9.1 and 9.2, the nominal stress is a broad minimum as the sample elongates and the neck narrows until it breaks. Here there is some evidence of an adiabatic temperature effect because the drawing stress and modulus are observed to fall if an already high shear rate is increased even further. 

Effect of aluminum content on room-temperature tensile elongation and hardness of binary y titanium aluminide alloys. Hardness values at 1000 °C (1830 °F0 are also shown. Note the single-phase y region and the two-phase (o +y) region. 

Note that with both the parent and weld metals the ultimate and yield strengths decreased between 300 K and 195 K. At room temperature the elongation was the same for both the annealed and weld specimens indicating that the large cross-sectional area of the weld specimen had no effect on the elongation. However, the elongation of the annealed specimen increased by a greater amount down to 76 K because the brittle weld metal is more temperature sensitive. 

Polymers exhibit a temperature-dependent elastic-viscoplastic behavior. Temperature effects can influence the stability of geotextUes. Both tensile strength and elongation... 

Zigzag chain formations can straighten out under stress, thus leading to larger elongations in elastomers. The temperature effects are also exhibited in the viscoelastic behavior of such polymers. 

Physical Factors. Unsatuiated elastomers must be stretched for ozone cracking to occur. Elongations of 3—5% are generally sufficient. Crack growth studies (10—18) have shown that some minimum force, called the critical stress, rather than a minimum elongation is required for cracking to occur. Critical stress values are neady the same for most unsaturated mbbers. However, polychloroprene has a higher critical stress value than other diene mbbers, consistent with its better ozone resistance. It has been found that temperature, plasticization, and ozone concentration have httie effect on critical stress values. 

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