中文摘要：

采用超音速火焰喷涂技术在不同丙烷流量下制备了3种TiB2-50Ni金属陶瓷涂层，并采用水淬法将3种TiB2-50Ni涂层在600和800℃条件下进行热震试验。通过扫描电子显微镜（SEM）和X射线衍射（XRD）对在不同条件下热震后的涂层进行表面和截面形貌观察及物相结构分析。研究结果表明，在600℃热震条件下，随着热震次数的增加，不同丙烷流量制备的3种涂层的裂纹扩展更为严重，且在热震循环次数为150次时，3种涂层表面和截面中均出现了扩展较为严重的交叉裂纹。在800℃热震条件下，3种涂层热震失效的热震循环次数明显减少，并且涂层的表面和截面产生的裂纹更长更宽。通过3种涂层的热震试验进一步发现，随着丙烷流量的增加，涂层的抗热震性能逐渐降低，其中以No．3涂层（丙烷流量为42L·min^-1）抗热震性能最差。通过对3种涂层热震后的XRD分析发现，3种涂层热震后的主要物相为TiB2和Ni两相，且随着在600℃热震循环次数的增加和热震温度的增加（800℃），涂层热震后产生的氧化物含量逐渐增多。

英文摘要：

Three kinds of TiB2-50Ni coatings were prepared by high velocity oxygen fuel （HVOF） process under different propane flows, and the thermal shock behavior of TiB2-50Ni coatings was investigated via water quenching method at thermal shock temperature of 600 and 800℃ . The surface and cross-sectional morphologies of coatings after thermal shock test were analyzed by scanning electron microscopy （SEM）. And X-ray diffraction （XRD） was employed to characterize the phase compositions of coatings. The results showed that with the increase of thermal shock cycles at 600 %, the cracks of three kinds of TiB2-50Ni coatings with different propane flows were propagated more seriously, and there were a network of cracks appeared in the coatings after 150 thermal shock cycles at thermal shock temperature of 600 ℃. The thermal cycles of three kinds of TiB2-50Ni coatings obviously decreased at thermal shock temperature of 800 ℃, and the surface and cross-sectional cracks were longer and bigger. With the increase of propane flow, the property of thermal shock of TiB2-50Ni coatings was degraded, especially the property of thermal shock of No. 3 coating with 42 L.min- propane flow was the worst. By analyzing the phase compositions of three coatings after thermal shock, the main phase compositions of the coatings were composed of TiB2 and Ni, and the oxide content gradually increased with the thermal shock cycles of 600℃and the thermal shock temperature （800℃ ） increasing.