Abstract
The ductile-brittle transition of an ethylene-hexene copolymer was measured from 80 to 24° C. The basic curves of stress against time to failure could all be unified in terms of a single equation based on normalizing the stress relative to the transition stress between the ductile and brittle regions and using a single thermal activation parameter. This unity is based on the observations which show that the ductile and brittle failure processes are both associated with a shear process. The unifying equation is
where σ c is the minimum stress for ductile failure at an arbitrary temperature, T R; t R is the time to failure at an arbitrary reference temperature T R; n equals 34 and 3.3 for the ductile and brittle regions, respectively and R is in J mol−1 K−1.
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References
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Lu, X., Brown, N. The ductile-brittle transition in a polyethylene copolymer. J Mater Sci 25, 29–34 (1990). https://doi.org/10.1007/BF00544180
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DOI: https://doi.org/10.1007/BF00544180