Effect of Layer Number on Microstructure and Mechanical Properties of TiC‐WC/TiC‐TiCN Laminated Ceramics

To improve fracture toughness (FT) and flexural strength (FS) of TiC‐based ceramics, TiC‐WC/TiC‐TiCN laminated ceramics (TWTTLCs) are fabricated by the layer‐making method and vacuum hot‐pressing sintering technology. The effects of layer numbers (LN) on residual stress, microstructure, and mechanical properties are investigated. The result shows that residual compressive stress (RCS) and residual tensile stress (RTS) layers are alternately distributed in TWTTLCs, and an increase in LN results in higher RCS and lower RTS. Small amounts of Ni and Mo are present in both the TiC‐WC layer (TWL) and the TiC‐TiCN layer (TTL). The main phases in TWL are TiC, (Ti, W)C, and (Ti, W, Mo)C, while in TTL are TiC, TiCN, and (Ti, Mo)C. The fracture of TWTTLCs is mainly characterized by intergranular and transgranular fractures. The number of microdefects in TWTTLCs is relatively small. As LN increases, Vickers hardness(VH), FT, and FS of TWTTLCs first increase and then decrease. When LN is 7, TWTTLC shows better comprehensive mechanical properties: the surface VH is 18.7 ± 0.1 GPa, the overall FT (OFT) is 8.74 ± 0.2 MPa m 1/2 , and FS is 1089.5 ± 10 MPa. This study demonstrates that the incorporation of a laminate structure in TiC‐based ceramic can effectively enhance its mechanical properties.