Microstructure of interface of SPS co-sintered and sinter bonded cp2-Ti and Co–28Cr–6Mo

Abstract

The interface of bimetallic CoCrMo/cp2-Ti discs produced by either co-spark plasma sintering (SPS) or SPS bonding at a nominal temperature of 1273 K is made of a bonding layer and a diffusion layer. The bonding layer is made of three sublayers with different Co, Cr, Mo and Ti contents. The diffusion layer is made of two layers with different microstructure: beta titanium close to interface and lamellar alpha–beta over the whole diffusion distance of Co, Cr and Mo. The measured diffusion profiles correspond to a slightly higher (40 K) temperature than the measured one into the die wall during sintering. Some residual porosity is observed in the cobalt alloy due to the effect of titanium, which sinters at a lower temperature, reducing the efficiency of the particular heating mechanism of SPS.

Keywords:

• Spark plasma sintering
• Co-sintering
• Sinter bonding
• Titanium
• Co alloy

The study is co-funded by Provincia Autonoma di Trento and Eurocoating SpA, Trento, as part of the SpaceCups project.