Investigations on Thermal Influences for Thixoforging and Thixojoining of Steel Components

Abstract

At the Institute of Metal Forming (IBF) current investigations within the framework of the Collaborative Research Centre 289 are mainly concentrated on forming of semi-solid precursor material of the steel grades X210CrW12 and 100Cr6. One important task is the precise temperature for the composition of solid and liquid phase fraction in the preheated billet. Experimental measurements and numerical simulations show significant heat losses during transport of the billet and after its insertion into the die. These developing temperature gradients influence strongly the resulting temperature field in the formed component. In case of the forming tools the critical increase of the temperature depending on the tool material is shown. As fundamental research in the field of thixojoining the temperature development of the inserts is analysed and demonstrates the feasibility of joining higher and lower melting materials into the semi-solid matrix.

Trend and Development of Semisolid Metal Joining Processing

“…The research effort has concentrated on the modelling of the process in order to achieve a better estimation of the actual temperature distribution and to provide an initial temperature field for the simulation of the forming operation and on developing a model that can be used for process optimization. For instance, Baadjou et al [22] derived input parameters for their finite element model, which included the whole process chain beginning with the heated billet and ending with the forming operation, by using Forge 2 software, which is based on Lagrange equations and uses a viscoplastic material behaviour to consider the strain rate and temperature dependence of plasticity. Therefore, the temperature distribution directly before forming has to be taken into account for numeric modelling of the forming operation, which can only be achieved by simulation of the complete process chain.…”

“…Simulated temperature gradient in (a) matrix of formed X210CrW12 and (b) tools and inserts after joining[22]. Joining metals using semisolid slurries[23].…”

Near‐net shaping of geometrically complex diving knife by semisolid steel casting using ceramic mould system

“…2 This is, presumably, owed to the initial strategy to substitute classical forging parts by SSM parts, as pursued by various authors. [4][5][6][7][8] Recently, Kapranos et al 9 emphasised the importance of careful product selection, and current research is focused on innovative process applications such as thixojoining 10 and biomedical implants, even for challenging work alloys such as intermetallic compounds. 11 However, steel thixoforming is still waiting for its breakthrough taking it from laboratory scale to industrial production.…”

Investigations on Semi‐solid Joined Steel Components and their Bonding Quality

“…Mechanical tests demonstrated a higher bonding strength with decreasing content of liquid phase fraction [1], which verifies a significant advantage compared to the compound casting technology with high liquid phase fraction. Also the feasibility of a joining semi-solid steel matrix with different steels and even lower melting materials like copper based alloys was shown in different research projects [4][5][6]. Figure 1 shows a steel component that contains a shaft made of steel (centre) and a bush made of copper alloy (circumferential in the lower part) [7].…”