Structural evolution of ZA27 alloy during semi-solid isothermal heat treatment

À´Ô´ÆÚ¿¯£ºÖйúÓÐÉ«½ðÊôѧ±¨(Ó¢ÎÄ°æ)2001ÄêµÚ1ÆÚ

ÂÛÎÄ×÷Õߣº³ÂÌå¾ü ÂíÓ± ºÂÔ¶ ½ËÉ Ðí¹ã¼Ã Ëï¾ü

ÎÄÕÂÒ³Â룺98 - 102

Key words£ºZA27 alloy; semi-solid state; isothermal heat treatment; structural evolution; spherical structure

Abstract: The structural evolution of ZA27 alloy modified by element Zr was studied during semiª²solid isothermal heat treatment, and its transformation mechanism was also discussed. The results indicate that the primary ¦Á phase changes from equiaxed grains to spherical grains gradually at semiª²solid temperature of 460. With increasing isothermal time, the eutectic between boundaries of¦Á phase diffuses toward ¦Á phase, and the primary equiaxed grain arms merge and boundaries tend to disappear to form near particle grains. Further, the eutectic left on ¦Á boundaries melts to make the near particle grains separate, and form spherical structure at last.