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将在不同丙烷流量条件下采用超音速火焰喷涂技术制备的3种TiB2-50Co进行热震试验,研究3种涂层在600℃不同热震循环次数和800℃条件下的抗热震性能,通过扫描电子显微镜和X射线衍射仪对3种涂层在不同条件下热震后的表面和截面形貌及物相结构进行分析,通过水淬法测试涂层的抗热震性能。结果表明,在600℃条件下,随着热震次数的增加,涂层中的表面和截面裂纹扩展随之更长而深,并在热震循环次数为150次时涂层中出现了网状或交叉裂纹;在800℃条件下,涂层热震失效循环次数明显减少,涂层中裂纹扩展更为严重,其中No.3涂层(丙烷流量为36L/min)抗热震性能最差。通过对3种涂层在不同热震条件后的XRD分析可知,涂层的主要物相为TiB2和Co两相,并发现涂层中存在一定的TiO2氧化相。
The thermal shock tests of three kinds of TiB2-50Co prepared by supersonic flame spraying at different flow rates of propane were carried out to study the thermal shock resistance of three kinds of coatings under different thermal shock cycles of 600 ℃ and 800 ℃, Scanning electron microscopy and X-ray diffraction were used to analyze the surface and cross-sectional morphology and phase structure of the three coatings after thermal shock under different conditions. The thermal shock resistance of the coatings was tested by water quenching method. The results show that with the increase of the number of thermal shocks, the surface and cross-sectional crack propagation in the coating grows deeper and deeper at 600 ℃. When the number of thermal shock cycles is 150, Or crack at 800 ℃. The number of cycles of thermal shock failure obviously decreases and the crack propagation is more serious at 800 ℃. The No.3 coating has the worst thermal shock resistance when the flow rate of propane is 36L / min. By XRD analysis of the three coatings under different thermal shock conditions, the main phase of the coating is TiB2 and Co two phases, and found that there is a certain TiO2 oxidation phase in the coating.