Ceramic/metal composites, as high-temperature structural materials, have limited applications because of their poor machinability . AlN/Mo/Mo 2 B machinable composites were fabricated by adding h-BN to AlN/Mo composites by plasma-activated sintering at various temperatures and at an axial pressure of 30 MPa under argon atmosphere. The sample sintered at 1500 °C exhibited excellent machinability for cemented carbide tools, with a bending strength of approximately 500 MPa and a Vickers hardness value of 9.34 GPa. The effects of sintering temperature on the microstructure, mechanical properties, and machinability were investigated, and the reactions introduced by adding h-BN were studied. These reactions reinforced the composite and newly introduced a Mo 2 B phase, which showed better ability to deflect cracks and prevent them from moving deep inside the composite, thus improving its machinability. This research provides a possible solution for improving the machinability of ceramic/metal composites without sacrificing the strength .
Given the insufficient wettability and compatibility between ceramic and metal, heterogeneous grain boundaries in particular composites consistently represent the primary failure sites related to both mechanical loading and chemical corrosion. To solve as above–mentioned problem and improve the interfacial bonding of ceramic/metal composites, we performed a novel strategy to modify the grain boundaries of AlN/Mo composites via Ni nanoparticles , which was produced via rotary chemical vapor deposition . Without sacrificing ductility, a substantial 46.1 % increase in bending strength was successful attained arises from the combined influence of grain boundary density and diffusion depth, interfacial structure and electronic properties. In view of the limitations of the traditional blending methods, this study made full use of random nucleation characteristics during the oxidation/reduction process in RCVD to form uniform nanoparticle coating on the surface of AlN powder, thereby avoiding potential risks to AlN/Mo composites, such as brittle intermetallic compounds , localized performance variations.