EFFECTS OF EXTRUSION CONDITIONS ON MECHANICAL-PROPERTIES IN ZR-AL-NI-CU GLASSY POWDER COMPACTS

We report on extrusion conditions such as the powder handling processi ng and extrusion ratio and temperature in the production of glassy aho y compacts by means of the warm extrusion of powders at a supercooled liquid state. The alloy used was a Zr65Al10Ni10Cu15 (at.%) glassy allo y which has a significant supercooled liquid region of 105 K. The glas sy powder compacts with almost the same tensile strength as the melt-s pun glassy ribbons or the as-cast glassy bulks were produced by an ext rusion in the supercooled liquid state at extrusion ratios above 4 by means of ordinary powder metallurgy processing. Closed processing, in which the powder was handled in a well-controlled atmosphere without b eing exposed to air, moreover, led to a higher level of strength as co mpared with ordinary processing, and full strength at extrusion ratios above 3, due to improvement in the powder particle bonding state. Thi s seems to greatly affect the future development of bulk amorphous all oys that have complex shapes and novel properties.