Analysis and evaluation of different influencing factors in processing of hollow and full beads based on TRIP steel

A novel and innovative process for full as well as hollow metal bead fabrication using gel-casting process by alginate gelation is presented. In particular the influence of four different alginates and various solidifying agents have been investigated regarding the formation and stability of full and hollow beads. The used suspension for bead fabrication contained a metastable austenitic steel powder (16Cr7Mn3Ni) as well as different alginates and was added dropwise into water containing different solidifying agents. With the aid of sodium and potassium alginate dropped in solution with CaCl2, full metal beads have been obtained. Hollow beads have been produced using potassium alginate and Ca(OH)2 as solidifying agent and show a hollow space fraction of 65%. At lower strains (up to 10%) hollow beads obtain higher specific energy absorption (SEA) in comparison to full ones.