Origin of high tension-compression yield asymmetry in as-extruded pure zinc

Zinc and its alloys have received increasing attention due to their potential to be applied as biodegradable implants. However, the distinct tension-compression yield asymmetry of zinc and its alloys after plastic forming is undesirable. Here we identify the strong tension-compression yield asymmetry in as-extruded pure zinc and reveal that higher {101¯2}〈1¯011〉twinning activity under tension is the underlying reason. Based on the finding, weakening texture and refining grains are put forward as effective strategies to reduce the tension-compression yield asymmetry.