• High-shape-retention Dia/Cu composite was obtained via BJ3DP combined with infiltration. • The shrinkage of the sample obtained by infiltrating 40 vol.% copper was within 1%. • The TC of the sample obtained by infiltrating 40 vol.% copper was 392 W·m -1 ·K -1 . Diamond/Cu (Dia/Cu) composites have emerged as a focal point in research on thermally conductive materials owing to their exceptional thermal conductivity, low coefficient of thermal expansion, and outstanding corrosion resistance. Considering the difficult machinability of diamond, binder jet 3D printing (BJ3DP) overcomes the machining limitations of conventional processes and constitutes an emerging near-net-shaping technology. In this study, to further improve the shape accuracy of printed parts, W-coated Dia/Cu composites were prepared using BJ3DP combined with melt-infiltration technology to explore the feasibility of using BJ3DP for preparing highly dense and low-shrinkage samples. The effects of different Cu melt-infiltration contents on the shrinkage and properties were investigated, and the optimum Cu melt-infiltration content was determined. The results showed that the shrinkage of the samples obtained by melt infiltration with 40 vol% Cu was within 1% in all directions, with better shape retention and a higher accuracy of the external dimensions. The relative density, thermal conductivity, coefficient of thermal expansion, and electrical conductivity of the samples measured by infiltrating with 40 vol% Cu were 96.68%, 392 W·m -1 ·K -1 , 8.18 × 10 -6 K -1 , and 32.3% IACS, respectively. This study demonstrates a fabrication route for low-shrinkage and high-shape-retention Dia/Cu composites by combining BJ3DP and melt infiltration. This strategy provides a simplified and effective method for achieving high-dimensional accuracy in other composites.
Gao et al. (Sun,) studied this question.