Mechanical properties and thermomechanical behaviour of SiCW/SiC composite dot-matrix structures moulded by selective laser sintering technology

In this study, SiC W /SiC composite dot-matrix structures containing in-situ SiC whiskers were prepared by the Selective Laser Sintering (SLS) technique and their mechanical properties were tested and simulated. The load of the designed dot-matrix structures (91×28×21 mm) was measured to be 1141.07 N at room temperature and 929.35 N, 838.01 N and 741.75 N at 1400 °C, 1600 °C and 1800 °C, respectively, with high temperature load loss of 18.55%, 26.56% and 35.00%, respectively. Through the simulation study, it is concluded that the temperature field distribution difference between the sequential heat-force coupling and full heat-force coupling of the dot-matrix structure is small, and the temperature field distribution gradually changes from the upper panel to the lower panel in the steady state temperature field, whereas the stress field distribution difference is large, and the difference lies in the fact that the thermal stress at the middle of the fully thermal - force coupled core is smaller than that at the middle of the sequential thermal - force coupled core, and is larger at the two ends. At the same time, the combination of full-field deformation measurement system and virtual simulation determines the failure form of the dot-matrix structure, which is mainly caused by cracks first appearing at the location of stress concentration and then extending to the entire dot-matrix structure until destruction.