This research developed an HDPE composite reinforced with Al2O3 and 1% SiC in the proportions of pure HDPE, 40 %, 50 % and 60 % of ceramic load. The mechanical flexural test showed results of sMAX 19.09 ± 2.89 MPa and E 1806 ± 400 MPa for the A60 group and concluded that with ceramic loadings above 60 % contribute to crystallization in the regions around the particles. TGA analysis showed initial degradation at 409 °C and final degradation between 499 and 504 °C, with a residue in pure HDPE of 0.46%. The DSC curves showed an endothermic peak at 132 °C and crystallization around 119 °C, and the crystallinity of the HDPE was 95.29 %, and the analyses showed a decrease in the enthalpy of fusion and crystallization with increasing ceramic loading due to the decrease in the polymer fraction in the composite. DMA analysis showed that temperatures above the Tg of the crystalline phases were the mechanism that contributed most to the storage modulus. FTIR analysis showed several interactions in different bands between the 3 compounds in the composite.