As a new self-healing agent

Ti

3

SiC

2

was added into yttria-stabilized zirconia (YSZ) thermal barrier coatings. By atmospheric plasma spraying (APS)

thick coatings were prepared using an YSZ–Ti

3

SiC

2

mixing powder. To observe oxidation and self-healing behavior

cracks were prefabricated on the surface of YSZ–Ti

3

SiC

2

coating by uniform external load. The prepared samples were then isothermally treated at 1050℃ in air. The phase and morphology evolution of the coatings

as well as the self-healing behavior were investigated

via several analyzing methods. The results showed that a part of Ti

3

SiC

2

was decomposed into amorphous SiO

2

and TiC after spraying and a double layered structure composed of a TiO

2

outer layer and a TiO

2

+SiO

2

inner layer was formed after isothermal treatment. In the process of self-healing

oxidation of the healing agent in the coating led to the growth of silicon oxide and titanium oxide in the cracks. These oxides gradually filled the cracks due to the diffusion-controlled oxidation. Meanwhile

the compressive stress induced by the volume expansion due to SiO

2

and TiO

2

growth in the crack enhanced the healing effect. Eventually the prefabricated cracks were healed.