EFFECT OF PROCESSING PARAMETERS ON THE EARING AND MECHANICAL-PROPERTIES OF STRIP CAST TYPE-3004 AL-ALLOY

Electrical resistivity, superficial hardness, tensile testing, and qua ntitative metallography techniques were used in this study. The strip cast type 3004 aluminum alloy received sixteen different thermomechani cal treatments before cups were drawn. The top edges of the drawn cups were not flat. Rather there were high points or ears with valleys bet ween them. The homogenization temperature varied form 510 to 621 degre es C at 24 h. Some samples received an additional 426 degrees C/24 h h omogenization anneal. Most specimens were rolled along the longitudina l direction of the as-cast material, and some were rolled in the trans verse direction. Most samples were recrystallized at 454 degrees C for 24 h in addition to the homogenization treatment. Some were recrystal lized for 168 h. All samples were subsequently rolled to 0.33 mm for c up drawing and percent earing determination. The percent earing result s of some samples were less than 1.5%, but the mechanical strength was also lowered. The high-temperature recrystallization anneal of 454 de grees C was the controlling factor in determining the earing and mecha nical strength of the final rolled sheet.