Properties with Annealing Temperature

Chapter I. (a) Variation in the mechanical properties (Tensile Strength, Elastic Limit, Elongation, Shock Resistance, and Hardness) with the amount of cold work. (6) Variation in these mechanical properties with annealing temperature (after cold work). 

Variation of these Mechanical Properties with Annealing Temperature. 

Fig. 56.—Variation in Mechanical Properties with Annealing Temperature. Metal quenched from 475°, reannealed, and cooled very slowly.

Flo. 45.—Variation in Mechanical Properties (Tensile and Impact) with Annealing Temperature. Metal subjected to 60 % Cold Work, annealed and cooled in air. 

Structural Properties at Low Temperatures It is most convenient to classify metals by their lattice symmetiy for low temperature mechanical properties considerations. The face-centered-cubic (fee) metals and their alloys are most often used in the construc tion of cryogenic equipment. Al, Cu Ni, their alloys, and the austenitic stainless steels of the 18-8 type are fee and do not exhibit an impact duc tile-to-brittle transition at low temperatures. As a general nile, the mechanical properties of these metals with the exception of 2024-T4 aluminum, improve as the temperature is reduced. Since annealing of these metals and alloys can affect both the ultimate and yield strengths, care must be exercised under these conditions. 

Poly(arylene ether ketone) and poly(arylene ether sulfone) were also tried to be incorporated into the hybrids with silica gel by means of the sol-gel procedure [19, 20], For example, triethoxysilyl-terminated organic polymer was subjected to co-hydrolysis with tetraethoxysilane. A systematic change in mechanical and physical properties of the hybrid glass has been found with the content of organic polymer and the annealing temperatures. 

Annealing can reduce the creep of crystalline polymers in the same manner as for glassy polymers (89,94,102). For example, the properties of a quenched specimen of low-density polyethylene will still be changing a month after it is made. The creep decreases with time, while the density and modulus increase with time of aging at room temperature. However, for crystalline polymers such as polyethylene and polypropylene, both the annealing temperature and the test temperatures are generally between... 

The effect of the annealing temperature on the initial modulus is also presented in Figure 20.8. The moduli of monofilaments annealed at 160 °C for 30 min are higher than those of normal monofilaments, because the matrix polymers are recrystallized with a low PHB content, and the LCP molecules in the domain are reoriented with a high PHB content. The thermal treatment of the PHB/PEN/PET fibers can be an effective way to improve the tensile properties, especially the tensile modulus, and high-speed winding may be a promising way to obtain fibers... 

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