Influence of Section Size on the Mechanical Properties and Fracture Toughness of 7075-T6 Aluminum, 6Al-6V-2Sn Titanium, and AISI 4340 Steel

The influence of section size on mechanical properties, yield strength, tensile strength, elongation, reduction of area, notched tensile ratios, and fracture toughness was determined for 7075-T6 aluminum, 6Al-6V-2Sn titanium, and AISI 4340 steel. The tests were made on smooth tension specimens with diameters from 0.113 to 3.57 inches, and sharply notched specimens with diameters from 0.160 to 5.05 inches. The tensile fracture topography of the smooth and notched specimens is illustrated and discussed. The data show that yield and tensile strengths are not changed appreciably by increasing section size, but ductility and toughness properties are affected.