(上海交通大學 金屬基復合材料國家重點實驗室，上海 200030)
摘 要: 采用大氣等離子噴涂方法制備不同類型的氧化釔部分穩(wěn)定氧化鋯熱障涂層：傳統(tǒng)涂層、納米團聚粉末制備的納米涂層和空心球粉末制備的空心球涂層。通過掃描電鏡、透射電鏡、壓汞儀和激光脈沖法觀察和測試各種涂層的組織形貌、空隙分布和導熱系數(shù)，并在相同條件下測試各種涂層的隔熱性能。結果表明：納米涂層空隙率最低，內(nèi)部孔洞細小。空心球涂層組織相對疏松，內(nèi)部層片更薄，有最高的空隙率和最大的平均空隙大小。傳統(tǒng)涂層介于二者之間。納米涂層和傳統(tǒng)涂層均表現(xiàn)出雙態(tài)空隙大小分布。涂層的導熱系數(shù)均隨著溫度的上升而升高。傳統(tǒng)涂層的熱導率最高，納米涂層與空心球涂層的熱導率相接近。納米涂層具有最好的隔熱性能，空心球涂層接近納米涂層的隔熱效果。隔熱效果與涂層厚度呈線性關系。隨著厚度增加，導熱系數(shù)低的納米涂層和空心球涂層的隔熱效果增長幅度高于傳統(tǒng)涂層。
關鍵字: 熱障涂層；大氣等離子噴涂；納米；空心球粉末；隔熱性能
（State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030, China）
Abstract:Different zirconia based thermal barrier coatings (TBCs) were fabricated by air plasma spraying including the conventional TBCs, the nanostructured TBCs from the reconstituted nanoparticles (the nano-coatings) and the special TBCs from the hollow spherical powder (the HSP coatings). The microstructures and properties of the different coatings were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP). Laser flash technique was used to examine the thermophysical properties of the different coatings. Thermal barrier effects for all the specimens were tested by a self-made device under the same conditions. The results reveal that the nanostructured TBC with the smallest micropores has the lowest porosity, whereas the HSP coatings show a relatively looser microstructure with the largest porosity and thinnest splats. Both the conventional coatings and the nano-coatings present a typical bimodal pore size distribution. In general, the thermal conductivities of all the coatings increase slightly with increasing temperatures. The conventional coating has the highest thermal conductivity among all the coatings. The thermal conductivity of the HSP coatings is similar to that of the nano-coatings. The nano-coatings show the best thermal barrier effect and the HSP coatings also present a good thermal barrier effect. The thermal barrier effect is proportional to the TBC’s thickness. With the increasing thickness of coatings, the thermal barrier effect increases more for the coatings with low thermal conductivity than that with high thermal conductivity.
Key words: thermal barrier coatings; air plasma spraying; nanostructure; hollow spherical powder; thermal barrier effect
