Effects of microporosity on the tensile properties of aluminum alloy

The influences of cooling rate, hydrogen inflating time, degassing time, inclusion content on the distribution of pores within the ingot, hydrogen content and the mechanical properties of 1050 aluminum alloy were investigated by tensile test, optical microscope(OM), scanning electron microscope(SEM). With the increasing inflating hydrogen time, the hydrogen content increases, while, the strengths and elongation decrease. With the increasing degassing time, the hydrogen content decreases, while, the strengths and the elongation increase. With increasing cast temperature, the hydrogen content remains constant at first and increases obviously from 720 degrees C to 760 degrees C, while the strengths and the elongation decrease gradually. The crack is mainly originated at outcrop of slip step, inclusion and porosity.