Influence Of Tool Geometry, Tool Coating And Process Parameters In Thixoextrusion Of Steel

Semi-Solid Extrusion of Complex-Shaped Steel Rods Using Ceramic Dies

“…The curve progression observed herein is consistent with findings of other authors in thixoextrusion of metals [12], yielding no evidence of a yield stress related to structural breakdown of the solid skeleton. The steep increase in extrusion force is attributed to the intrinsic rise in viscosity near the end of extrusion due heat losses of the semi-solid slurry via the extruded rod and simultaneous reduction of heat being stored in the remaining billet.…”

Semi-solid extrusion of steel grade X210CrW12 under isothermal conditions using ceramic dies

“…Thixotropic material flow consequently leads to a characteristic shape of the load-displacement-curves during extrusion that significantly differs from typical curves in hot extrusion: Instead of a steep increase in forces at the onset of forming followed by a steady state at nearly constant force values a continuous, exponential increase in ram forces is observed, as reported by Knauf et al (2007). This is confirmed by the shape of the load-displacement diagram obtained in current experiments at liquid phase contents of approximately 55% that corresponds to typical curves presented by Gullo et al (2000), for non-segregating semi-solid extrusion at liquid fractions >40%.…”

A Review on Thixoforming of High Melting Point Alloys

“…Since 1998 the subject has gained a great enthusiasm, the study of steel thixoforming has then become an important topic within the SSM research areas. Several research teams, mainly in Europe and Asia, have been involved in the development of this process (Kapranos, Kirkwood and Atkinson in the UK [8][9][10][11][12][13][14][15], Kopp, Hirt, Püttgen, and Modigell in Germany [16][17][18][19][20][21][22][23][24][25], Bigot, Favier in France [26][27][28][29][30], Rassili in Belgium [31][32][33][34][35], Omar in Malysia [36], Li in China [37]).…”