## 1 Introduction  
Natural flake graphite has excellent physical and chemical properties, such as thermal conductivity, electrical conductivity, high-temperature resistance, and corrosion resistance. It is widely used in iron and steel casting, aviation, and aerospace fields [1; 2; 3; 4; 5]. It is well known that the natural flake graphite powder is challenging to process and form due to the weak self-adhesive ability and poor formability, so the value of natural flake graphite needs to be realized by proper forming technology. At present, hot pressing and cold pressing are the main processes for forming natural flake graphite [6; 7]. The graphite blocks, prepared by hot pressing at 2773 K with natural graphite powder and chopped carbon fibers as raw materials and asphalt as a binder, have proper bending and compressive strength perpendicular to the direction of graphite layer, up to 39.6 MPa and 65.5 MPa, respectively, with 8 wt % chopped carbon fibers [8]. The thermal conductivity of the graphite bulk composites, prepared by uniaxial cold compression molding using natural flake graphite powder, synthetic graphite powder as the raw material, and liquid phenolic resin as its binder, is measured by the Xenon Flash Method to be 19-30 W\(\cdot\)m\({}^{-1}\)K\({}^{-1}\) in the range of 100-1000 \({}^{\circ}\)C [9]. However, the simple graphite product can be made by the above processes, but the complex one can not. The emergence of selective laser sintering (SLS) makes it possible to obtain complex structure graphite parts with natural flake graphite as the raw material. SLS is a kind of rapid prototyping technology that is widely used to fabricate the complicated preforms or parts with the powder or powder that can bond each other under the hot action during the laser-scanning process. There are a wide range of materials available for selective sintering, including paraffin powder, plastic powder, metal powder, and ceramic powder. For example, according to [PERSON] et al. [10], the graphite/phenolic resin composite bipolar plate for fuel cells can be prepared by SLS with phenolic resin and natural flake graphite, which has been successfully applied in industrial production. Our previous study showed that the effects of process parameters such as laser power, scan speed, scan spacing, and layer thickness on the mechanical properties of SLS graphite parts and pointed out that the bending strength of samples directly formed by SLS can reach 2-3 MPa when the laser power is 20 W, scan speed is 2000 m/s, scan spacing is 0.1 mm, and layer thickness is 0.15 mm [11]. These composite parts formed with graphite/phenolic resin have a typical porous structure, and this porous structure can improve the thermal isolation (approximately 0.73 W.m\({}^{-1}\)K\({}^{-1}\)) but reduce the strength (compressive strength approximately 2.1 MPa and flexural strength approximately 2.5 MPa), so it is difficult to fabricate parts meeting both functional and structural requirements directly by the SLS process. In order to solve the contradictory influence of porous structure on thermal performance and structural performance, the related research work has been mainly carried out from the following two aspects: mixture powder formula composition and post-treatment process. [PERSON] et al. [12; 13] found that when the mixture powder composition is 45 vol.% of natural flake graphite, 10 vol.% of carbon fiber, 10 vol.% of synthetic graphite, and 35 vol.% of binder, the comprehensive performance of the fuel cell composite bipolar plate prepared by SLS is similar to that of the bipolar plate prepared by hot pressing. [PERSON] et al. [10] found that the infiltration of the preform sintered by SLS in liquid epoxy resin after carbonization can greatly improve the mechanical properties such as the bending strength up to 50 MPa, but it had little effect on the electric conductivity. [PERSON] and [PERSON] [14] also conducted related research. In this paper, 3D graphite/ceramic composite parts were fabricated by SLS.