Research on 3D printing process and properties of diamond–resin composites based on digital light processing

Additive manufacture of diamond tools has rarely been investigated to date. In this study, ultraviolet (UV) curable diamond–resin slurries with diamond contents from 6.25 to 25 vol% have been prepared to produce diamond-resin composites via 3D printing using digital light processing. The rheological properties and cure behavior of UV-curable slurries were examined. The results demonstrated that all slurries exhibited typical shear-thinning behavior, and the viscosity of each corresponding slurry noticeably increased as the diamond content increased from 0 to 25 vol%. Regarding the cure behavior, the cure depth and cure width of the slurries were increased and decreased by increasing the exposure time and solid loading, respectively. The mechanical and thermal properties of printed specimens were then characterized. The flexural strength of specimens decreased from 40 to 23.9 MPa with increase in the diamond contents from 0 to 18.75 vol% and appeared to plateau above 18.75vol% of diamond loading. Although the flexural strength increased with increase in the exposure time from 2 to 10 s, the optimal exposure time was 4 s. The geometric accuracy gradually decreased, and specimen deformation occurred when the exposure time exceeded 4 s. Results of the thermogravimetric analysis indicated that the addition of diamond to the slurry improve the specimens thermal stability.