Correlation between microstructure, chemical components and tribological properties of plasma-sprayed Cr 2 O 3 -based coatings
Correlation between microstructure, chemical components and tribological properties of plasma-sprayed Cr 2 O 3 -based coatings
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DOI：
10.1016/j.ceramint.2018.03.004
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发表时间：
2018-06
影响因子：
5.2
通讯作者：
Xiong Yang;Jinyan Zeng;Hao Zhang;Jinshuang Wang;Junbin Sun;S. Dong;Jianing Jiang;Longhui Deng
中科院分区：
文献类型：
--
作者：
Xiong Yang;Jinyan Zeng;Hao Zhang;Jinshuang Wang;Junbin Sun;S. Dong;Jianing Jiang;Longhui Deng
通过掺杂改性、改变结构尺寸等方法可以提高Cr2 O3涂层的耐磨性。此外，采用等离子喷涂和干冰喷射相结合的方法，从纳米结构原料中制备了Cr2 O3涂层。通过对等离子喷涂Cr2 O3基涂层的孔隙率、硬度和摩擦学性能的研究，探讨了涂层的显微组织、化学成分与摩擦学性能之间的关系。结果表明，在相同的等离子喷涂条件下，添加添加剂的复合涂层比纯Cr2 O3涂层具有更高的显微硬度和更低的孔隙率。CeO 2组分被发现，以提高Cr2 O3涂层的耐磨性，而Nb 2 O 5掺入对应于一个陡峭的摩擦系数上升。Cr_2O_3和Nb_2O_5薄膜的热膨胀系数（CTE）的不匹配促进了疲劳裂纹的萌生和微裂纹坑的形成。虽然组合工艺促进孔隙率降低，但纳米结构Cr2 O3（n-Cr2 O3）涂层呈现出比微米涂层更低的显微硬度，这是由于与微米级涂层相比，纳米结构Cr2 O3（n-Cr2 O3）涂层由于不充分的等离子体功率而具有松散的微观结构。微米和纳米Cr2 O3涂层的磨损机制均为疲劳裂纹和材料转移。
The wear resistance of chromium oxide (Cr2O3) coatings could be improved by doping modification and changing the structural scale, etc. In this study, micrometric Cr2O3coatings were doped with different additives, CeO2and Nb2O5. Moreover, Cr2O3coatings were deposited from nanostructured feedstock by the combination process of plasma spraying and dry-ice blasting. The correlation between the microstructure, chemical components and tribological properties of plasma-sprayed Cr2O3-based coatings was discussed based on the investigation of their porosity, hardness and friction behaviors. The results showed that the composite coatings doped with additives exhibited a higher microhardness, corresponding to a lower porosity than pure Cr2O3coating under the identical plasma-spray condition. CeO2constituent was found to improve the wear resistance of Cr2O3coating while Nb2O5incorporation corresponds to a steep rise in the friction coefficient. The mismatch of coefficient of thermal expansion (CTE) between Cr2O3and Nb2O5lamellae facilitated the origin of fatigue cracks and the formation of microfracture pits. Although the combination process promotes a porosity reduction, the nanostructured Cr2O3(n-Cr2O3) coatings present a lower microhardness than micrometric coatings, due to their loosen microstructure from insufficient plasma power compared to microscaled coatings. The wear mechanisms of both the micro- and nanometric Cr2O3coatings are fatigue cracks and material transfer.