Due to the substantial brittleness of the thermal sprayed coatings, fracture mechanic can effectively illustrate the applicability of such surface layers. Lanthanum-cerium oxide (LC) coatings usually show poor thermal sock behavior even at low temperatures, mainly induced by their low fracture toughness and decreased coefficient of thermal expansion. At the first step, this study deals with the solid state synthesis of LC. At the next step, the synthesized LC and YSZ used to apply composite coatings (monolithic LC, 75 wt% LC-25 wt% YSZ, 50 wt% LC-50 wt% YSZ, 25 wt% LC-75 wt% YSZ and monolithic YSZ) through thermal spray method. The fracture toughness and thermal shock resistance of the formed coatings were then investigated. X-ray diffraction spectroscopy, energy dispersive spectroscopy and field emission scanning electron microscopy were used to study the phase analysis, chemical composition and morphological investigations of the coatings, respectively. Results indicated that higher fraction of YSZ can lead to enhanced fracture toughness due to higher energy relieving rate. The best thermal shock resistance outcome was also achieved in LC-50 wt% YSZ composite coating, as the coating tolerated 350 thermal cycles.

由于热喷涂涂层的脆性，断裂力学可以有效地说明这种表面层的适用性。镧-二氧化铈（LC）涂层即使在低温下也通常表现出较差的热变形性能，这主要是由于它们的低断裂韧性和降低的热膨胀系数引起的。第一步，这项研究涉及LC的固态合成。在下一步中，合成的LC和YSZ用于涂覆复合涂料（整体式LC，75 wt％LC-25 wt％YSZ，50 wt％LC-50 wt％YSZ，25 wt％LC-75 wt％YSZ和整体式YSZ）通过热喷涂方法。然后研究了形成的涂层的断裂韧性和抗热震性。X射线衍射光谱 用能谱仪和场发射扫描电镜分别研究了涂层的相分析，化学成分和形貌研究。结果表明，较高的YSZ分数可以提高能量释放率，从而提高断裂韧性。在LC-50 wt％YSZ复合涂层中，由于涂层可承受350个热循环，因此也获得了最佳的耐热冲击性能。