Ag-toughened glass-ceramic coatings with excellent oxidation and spallation resistance under thermal shock at 700 °C

Glass-ceramics, known for their thermal stability and strong adhesion to metal substrates, are widely used as protective coatings for high-temperature application. But they usually suffered from inherent brittleness and high susceptibility to cracking. Traditional approaches to improve fracture toughness via incorporation of metal particles have often failed due to the ongoing reactions between the particles and the corrosive media. In this study, thermal shock resistance was significantly enhanced by doping oxidation-resistant soft metal particles, specifically Ag. The interface crystallization increases bonding strength, ensures complete plastic deformation of Ag particles under thermal stress, thereby enhancing fracture toughness and preventing matrix cracking. After 100 thermal shock cycles at 700 °C, the Ag-doped glass-ceramic coating exhibited superior performance, with high oxidation resistance, no crack initiation and a minimal mass loss of 0.04 mg/cm². This approach addresses the brittleness challenge of glass-ceramics, while fully utilizing the advantage of oxidation resistance.