Melt Spinning Processing Equipment And The Structure Of Mg-5%Zn Alloy Produced By RSP

Melt Spinning Processing Equipment (MSPE) was designed and manufactured in order to study the strengthening mechanisms of high strength Mg alloys produced by rapidly quenched solidification. The MSPE mainly consisted of melting part, single-roller part, vacuum part and control part. By using Mg-5%Zn alloy in this paper, the reliability of self-made MSPE and the process of producing ribbons were examined, as well as the factors that have influence on forming ability of sound ribbons were discussed. The microstructure of the rapid solidified Mg-5%Zn alloy was analyzed. The following results were concluded.We adopt an inner-heating resistance style of the heater for the melting part of the MSPE in a vacuum state. The power of the furnace is 2kw. The furnace meets the experimental need; The single-roller is droved by magnetic force which specially designed for the MSPE; Its vacuum value amount to ~10~'Pa; The equipment is controlled by an AI artificial intelligence adjuster.The optimized experimental processes consist of (1) the spraying pressure of Ar is O.OSMPa; (2) the melting temperature of Mg-5%Zn alloy is 760癈; (3) the rotation speed of single roller is 2840rpm; (4) the gap between the nozzle and the top of the surface of the roller is about 50|im.The rapidly solidified microstructure consists of uneven grains withingrain diameters between 10 and 50 um. Because the copper cooler has no effectively catalytic effect on the nucleation of the alloy, the grains on the quenching side are coarser than those on the free cooling side.consist of "beehive-like" microsegregation grains. The uniform "beehive-wall" contains higher Zn than that of the "beehive-room".The undercooling is calculated by adopting the BCT model. The results show that when the undercooling is more than 9IK, there are rapidly solidified microstructures in the Mg-5%Zn alloy.