1.8 Ductility measurement PDF

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1.8 Ductility measurement The ductility value of a material can be described as the ability of the material to suffer plastic deformation while still being able to resist applied loading. The more ductile a material is the more it is said to have the ability to deform under applied loading. The ductility of a metal is usually measured by its percentage reduction in cross-sectional area or by its percentage increase in length, i.e. AI  AF 100% A I percentage reduction in area = = and LI  LF 100% L I percentage increase in length = where AI = initial cross-sectional area of the tensile specimen AF = final cross-sectional area of the tensile specimen

LI = initial gauge length of the tensile specimen LF = final gauge length of the tensile specimen It should be emphasized that the shape of the tensile specimen plays a major role on the measurement of the ductility and some typical relationships between length and character for tensile specimens i.e. given in Table 1.1.

area = crosssectional area D * I ,= initial diameter of the tensile specimen Materials such as copper and mild steel have high ductility and brittle materials such bronze and cast iron have low ductility...