Ductility enhancement

Figure 7. Hydrogen-induced ductility enhancement of the Ti-6Al-2Zr-1.5V-lMo alloy in torsion tests at temperatures 607° - f, 660° - 2, 720° - 3 and 780°C - 4-...

Brena, S.F., and Schlick, B.M. (2007). Hysteretic behavior of bridge columns with FRP-jacketed lap splices designed for moderate ductility enhancement . Journal of Composites for Construction, 11(6) 565-574. 

Haroun, M.A. and Elsanadedy, H.M. (2005b). Fiber-reinforced plastic jackets for ductility enhancement of reinforced concrete bridge columns with poor lap-splice detailing . Journal of Bridge Engineering, 10(6) 149-151. 

FRP wrapping for axial compression strengthening and ductility enhancement (Fig. 22.7(d)). 

If contact with a rough surface is poor, whether as a result of thermodynamic or kinetic factors, voids at the interface are likely to mean that practical adhesion is low. Voids can act as stress concentrators which, especially with a brittle adhesive, lead to low energy dissipation, i/f, and low fracture energy, F. However, it must be recognised that there are circumstances where the stress concentrations resulting from interfacial voids can lead to enhanced plastic deformation of a ductile adhesive and increase fracture energy by an increase in [44]. 

Hydrogen effect on the mechanical properties results in markedly enhanced ductility and lowered flow stress of the alloys therefore they become workable at much lower temperatures. 

Polypropylene (PP) is a crystalline polymer suitable for low-stress applications up to 225°F (105°C). For piping applications this polymer is not recommended above 212°F (100°C). Polypropylene is shielded, pigmented, or stabilized to protect it from uv light. Polypropylene is often a combination of polyethylene and polypropylene which enhances the ductility of the polymer. 

Soften and render products more flexible by reduction of the brittleness of the end-product. Also used to modify viscosity and improve the flow characteristics and processability of a polymer. Are designed to space out the polymer molecules, facilitating their movements and leading to enhanced flexibility (lower modulus) and ductility. Plasticisers may play a dual role as stabilisers or cross-linkers. Performance criteria are compatibility, plasticising efficiency, processability and permanence. 

Impact modifiers for PET are generally elastomeric compounds that increase impact strength and elongation while usually decreasing modulus. An effective way to enhance the impact strength and to induce a brittle/ductile transition of the fracture mode, is by the dispersion of a rubber phase within the PET matrix. The... 

Uses. Strontium master alloys are used in Al foundry practice. As an addictive to Al-Si alloys, it enhances mechanical properties and machining performance it modifies the morphology of the eutectic from coarse acicular plates of Si to a fine interconnected fibrous morphology, resulting in higher tensile strength and greatly improved ductility. 

The microductile/compliant layer concept stems from the early work on composite models containing spherical particles and oriented fibers (Broutman and Agarwal, 1974) in that the stress around the inclusions are functions of the shear modulus and Poisson ratio of the interlayer. A photoelastic study (Marom and Arridge, 1976) has proven that the stress concentration in the radial and transverse directions when subjected to transverse loading was substantially reduced when there was a soft interlayer introduced at the fiber-matrix interface. The soft/ductile interlayer allowed the fiber to distribute the local stresses acting on the fibers more evenly, which, in turn, enhanced the energy absorption capability of the composite (Shelton and Marks, 1988). 

Mascia, L., Dhillon. J. and Harper, J. (1993). Adhesion enhancement of rubbery and ductile polyolefin coatings on glass fibers for epoxy composites and effects on failure mechanisms. J. Appi Polyin. Sci. 47, 487-498. 

Intermetallic alloys (compounds) are becoming of increasing interest as materials which possess significantly enhanced high temperature capabilities compared to many conventional metallic alloys. However, they suffer intrinsic problems associated with low-temperature ductility and fracture toughness. Two types of... 

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