Process optimization and study of the co-sintering behaviour of Cu-Ni multi-material 3D structures fabricated by spark plasma sintering (SPS)

Abstract

The present work focuses on the possibility of manufacturing multi-material structures by spark plasma sintering (SPS), thereby broadening the field of application of this process by taking full advantage of the specific properties of individual materials. As a combination of dissimilar materials to be co-processed, CuCrZr and nickel are of particular scientific and technological interest. For the processing of complex 3D multi-material geometries made of highly dissimilar materials, the sintering behavior of each individual material should however be as identical as possible. Since both materials have different physical and mechanical properties, the sintering behavior of the two individual powder materials is first characterized at different uniaxial pressures, heating rates and holding times. A strategy to determine optimal sintering conditions for the processing of multi-material structures is then developed, based on representation of the densification data of each material in the form of master sintering curves (MSC) and surfaces (MSS). From the MSS, an optimal uniaxial pressure of 35 MPa was determined and the holding time to achieve dense multi-material structures at a temperature of 1223 K was estimated. Different configurations of CuCrZr-Ni multi-material samples were successfully sintered using these parameters and microscopic analyses showed that the relative density in these parts is >99.8, in both CuCrZr and Ni.

Keywords

• Multi-material
• Spark plasma sintering
• Sintering behavior
• Master sintering curve
• Master sintering surface